JP2015527597A - Control of multiple light sources of directional backlight - Google Patents

Abstract

An imaging directivity comprising: an array of light sources; and a control system configured to provide a variable distribution of light flux across the array of light sources that is inversely scaled by a width associated with each of the lateral light sources. A backlight is disclosed. The light distribution of multiple output optical windows can be controlled to provide the desired luminance distribution on the window surface of the autostereoscopic display, and the directional display operates in wide-angle 2D mode, privacy mode, and low power consumption mode can do. Image quality can be improved and power consumption can be reduced.

Description

  The present disclosure relates generally to illumination of spatial light modulators, and more particularly to directional backlights for providing a wide range of illumination from multiple local light sources for use in 2D, 3D and / or autostereoscopic display devices. .

  A spatially multiplexed autostereoscopic display device typically includes a lenticular screen, or a parallax component such as a parallax barrier, at least a first set and a second set of pixels on a spatial light modulator, such as an LCD. Align with the array of images arranged as. The parallax component directs the light from each set of pixels in different respective directions and provides a first field window and a second field window in front of the display. The observer can see the first image with light from the first set of pixels from the eye placed in the first viewing window and from the eyes placed in the second viewing window, the second of the pixels. A second image can be seen with light from the set.

  Such a display device has a small spatial resolution compared to the original resolution of the spatial light modulator, and the structure of the viewing window is determined by the aperture shape of the pixel and the parallax component imaging function. For example, gaps between electrodes of electrodes typically produce non-uniform field windows. Such a display shows unnecessary flickering of the image according to the lateral movement of the viewer relative to the display, limiting the visual freedom of the display. Such flicker can be reduced by defocusing the optical element, but such defocusing increases the level of image crosstalk and increases visual fatigue for the observer. Such flicker can be reduced by adjusting the shape of the pixel aperture, but such changes reduce the brightness of the display and include addressing electronics within the spatial light modulator. There is.

  According to a first aspect of the present disclosure, a method for controlling an array of directional backlight light sources is provided. The directional backlight may include a waveguide having an input end, and the array of light sources may be disposed at different input positions in a lateral direction across the input end of the waveguide. The waveguide may have opposing first and second guide surfaces for directing light along the waveguide. A plurality of waveguides pass through the first guide surface using input light from a plurality of light sources as output light in an output direction distributed in a direction transverse to a normal to the first guide surface determined mainly by the input position. Can be configured to be oriented within the optical window. The method includes selectively manipulating a plurality of light sources to direct light into a plurality of varying optical windows corresponding to an output direction, the plurality of light sources being associated with each of the plurality of lateral light sources. It can be controlled to output light having a luminous flux that is inversely scaled by a given width and varies across the array of light sources.

  In some embodiments, from a waveguide that corrects display brightness variation with viewing angle and exhibits a non-Lambertian light output characteristic when illuminated to an array of light sources having a uniform luminous flux across the array of light sources A backlight having the Lambertian characteristic can be realized. Conveniently, the backlight appears to have a similar appearance as paper and can be seen comfortably because each observer's eyes can recognize the lighting structure with the same perceived image brightness. be able to.

  In other embodiments, the backlight brightness can be reduced relative to the off-axis viewing position at a faster rate than the Lambertian characteristic. As a comparison, such a backlight can achieve substantially lower power consumption compared to a Lambertian output backlight.

  In embodiments where the viewer is tracked, the backlight can achieve a Lambertian lighting appearance for a given viewing position, while the intensity change with viewing position can vary in a non-Lambertian manner. . Advantageously, the image can be viewed very comfortably, while the power consumption of the backlight can be reduced compared to a Lambertian display.

  In further embodiments, the brightness of the backlight can be configured to vary across the viewing window, reducing crosstalk of autostereoscopic images while achieving an acceptable level of image flicker for a moving observer.

  According to another aspect of the present disclosure, a directional display device is provided in which a control system is configured to perform a similar method.

  According to another aspect of the present disclosure, a method for controlling an array of light sources of a directional backlight is provided. A directional backlight can include a waveguide having an input end and an array of light sources disposed at different input locations in a lateral direction across the input end of the waveguide. The waveguide is configured to reflect the input light from the plurality of light sources and to return the light through the waveguide, by opposing first and second guide surfaces for guiding light along the waveguide. And a reflection end opposite to the input end. After the reflection from the reflection end in the output direction distributed in the horizontal direction with respect to the normal to the first guide surface, which can be determined mainly by the input position, the input light from the plurality of light sources is used as the output light. It can be configured to be oriented in a plurality of optical windows through one guide surface. The method selectively manipulates a plurality of light sources to supply a plurality of light sources with a drive signal that directs light into a fluctuating optical window corresponding to the output direction, and after reflection from the reflective end, a plurality of Sensing light incident on the input end from the light source. The drive signal can be calibrated according to the sensed light incident on the input.

  The scaled luminous flux of the light source array may vary spatially due to brightness and chromaticity non-uniformities between each of the light sources of the array. This embodiment can advantageously realize calibration of variations between the respective light fluxes of the light source, thereby realizing control of the scaled light flux of the light source, which can vary in a uniform manner for the observer. An optical output can be provided. Further, the scaled luminous flux may vary with time due to, for example, the aging effect of the light source. This embodiment can achieve in-field correction of the aging effect of the light source, advantageously leading to extended device life and output uniformity. A small number of detectors can be used during the calibration process to monitor the entire array and reduce costs.

  In sensing the light incident on the input end, a plurality of sensor elements arranged in the input end region outside the array of lateral light sources can be used. In another example, in sensing light incident on the input end, a plurality of sensor elements arranged in the region of the input end outside the array of lateral light sources on either side of the array of light sources can be used. In yet another example, an array of light sources that are not operated simultaneously may be used in sensing light incident on the input. The level of the drive signal can be calibrated so that the plurality of light sources output light having a luminous flux having a predetermined distribution across the array of light sources.

  According to another aspect of the present disclosure, a directional backlight device is provided in which the control system is configured to perform a similar method.

  Embodiments herein can provide an autostereoscopic display having a large area and a thin structure. Furthermore, as described below, the optical valve of the present disclosure can achieve thin optical components with a large back working distance. Such components can be used for directional backlights and provide directional displays including autostereoscopic displays. Furthermore, embodiments can provide controlled light illuminators aimed at efficient autostereoscopic displays and efficient 2D image displays.

  Embodiments of the present disclosure can be used in various optical systems. Embodiments may include various projectors, projection systems, optical components, displays, microdisplays, computer systems, processors, self-contained projector systems, visual systems and / or audiovisual systems, and electrical and / or optical equipment. Or may work with them. Aspects of the present disclosure can be used substantially in a wide variety of devices associated with optical and electrical devices, optical systems, presentation systems, or any device that can include any type of optical system. Thus, embodiments of the present disclosure can be used in visual systems and / or optical devices used in visual and / or optical presentations, visual peripherals, etc., as well as numerous computer environments.

  Before proceeding to the various embodiments disclosed in detail, it is to be understood that the disclosure is not limited to the details of the particular configuration shown, in application or fabrication, as other embodiments are possible. Furthermore, the disclosed aspects may be described in various combinations and configurations to define unique and specific embodiments. Further, the terms used in this specification are for the purpose of explanation and not for the purpose of limitation.

  Directional backlights typically provide control over illumination emitted from substantially the entire controlled output surface by modulation of independent LED light sources arranged on the input aperture side of the optical waveguide. Control of synchrotron radiation directivity distribution allows one person to view the display from only a limited range of viewing angles, viewing only one security function, illumination only over a small angle directivity distribution High electrical efficiency when provided, browsing of time-series stereoscopic and autostereoscopic displays with the left and right eyes alternating, and low cost can be realized.

  Various aspects and features of the present invention may be utilized together in any combination.

  The foregoing and other advantages and features of the present disclosure will be apparent to those of ordinary skill in the art upon reading this disclosure in its entirety.

For the purpose of illustration, embodiments are shown in the accompanying drawings, in which like reference numerals refer to like parts.
FIG. 6 is a schematic diagram illustrating a front view of light propagation in one embodiment of a directional display device in accordance with the present disclosure. 1B is a schematic diagram illustrating a side view of light propagation in one embodiment of the directional display device of FIG. 1A in accordance with the present disclosure. FIG. 5 is a schematic diagram illustrating, in plan view, light propagation in another embodiment of a directional display device in accordance with the present disclosure. 2D is a schematic diagram illustrating light propagation in a front view of the directional display device of FIG. 2A in accordance with the present disclosure. 2D is a schematic diagram illustrating light propagation in a side view of the directional display device of FIG. 2A in accordance with the present disclosure. 1 is a schematic diagram illustrating a directional display device in side view according to the present disclosure. FIG. 6 is a schematic diagram illustrating, in a front view, the generation of a viewing window in a directional display device including a plurality of curved light extraction mechanisms according to the present disclosure. FIG. 6 is a schematic diagram illustrating, in a front view, the generation of a first field window and a second field window in a directional display device including a plurality of curved light extraction mechanisms according to the present disclosure. 6 is a schematic diagram illustrating the generation of a first viewing window in a directional display device including a plurality of linear light extraction mechanisms in accordance with the present disclosure. FIG. 6 is a schematic diagram illustrating one embodiment of generating a first viewing window in a time division multiplexed directional display device in accordance with the present disclosure. FIG. 6 is a schematic diagram illustrating another embodiment of generating a second viewing window in a time division multiplexed directional display device at a second time slot in accordance with the present disclosure. 6 is a schematic diagram illustrating another embodiment of generating a first viewing window and a second viewing window in a time division multiplexed directional display device in accordance with the present disclosure. 1 is a schematic diagram illustrating an observer tracking autostereoscopic display device in accordance with the present disclosure. 1 is a schematic diagram illustrating a multi-viewer directional display device according to the present disclosure. 1 is a schematic diagram illustrating a privacy-oriented display device in accordance with the present disclosure. 1 is a schematic diagram illustrating a structure of a directional display device in a side view according to the present disclosure. 1 is a schematic diagram illustrating a front view of a wedge-type directional backlight according to the present disclosure. 1 is a schematic diagram illustrating a side view of a wedge-type directional display device according to the present disclosure. 1 is a schematic diagram illustrating a control system for an observer tracking directional display device in accordance with the present disclosure. 1 is a schematic diagram illustrating a plan view of a directional display including a directional backlight according to the present disclosure. 4 is a schematic diagram illustrating a graph of optical window intensity versus viewing position on a window surface in accordance with the present disclosure. 6 is a schematic diagram illustrating a graph of optical window luminous intensity versus viewing position on a window surface and a method of adjusting a light flux of a light source in an array in accordance with the present disclosure. 4 is a schematic diagram illustrating a luminous flux distribution graph for an array of light sources and a method for adjusting the luminous flux of the light sources in the array in accordance with the present disclosure. 15B is a schematic diagram illustrating details of FIG. 15B in accordance with the present disclosure. FIG. 6 is a schematic diagram illustrating a graph of luminous flux distribution and a front view of a directional backlight aligned with the luminous flux distribution in accordance with the present disclosure. FIG. 6 is a schematic diagram illustrating a graph of luminous flux distribution for an autostereoscopic Lambertian display system in accordance with the present disclosure. FIG. 6 is a schematic diagram illustrating a luminous flux distribution graph for an autostereoscopic display system having a gain greater than 1 and an on-axis viewing position in accordance with the present disclosure; FIG. 6 is a schematic diagram illustrating a luminous flux distribution graph for an autostereoscopic display system having a gain greater than 1 and an off-axis viewing position in accordance with the present disclosure; FIG. 6 is a schematic diagram illustrating a further graph of luminous flux distribution for an autostereoscopic display system having a gain greater than 1 and an off-axis viewing position in accordance with the present disclosure. 1 is a schematic diagram illustrating a light source addressing device in accordance with the present disclosure. FIG. 6 is a schematic diagram illustrating a graph of luminous intensity for each of an array of optical windows and an optical window in accordance with the present disclosure. FIG. 6 is a schematic diagram illustrating a graph of optical window luminous intensity versus viewing position for a waveguide including uniform luminous intensity of a plurality of light sources in accordance with the present disclosure. FIG. 6 is a schematic diagram illustrating a perspective view of light rays incident in a first direction on a light extraction mechanism of a waveguide according to the present disclosure. FIG. 6 is a schematic diagram illustrating a perspective view of light rays incident in a second direction on a light extraction mechanism of a waveguide according to the present disclosure. FIG. 6 is a schematic diagram illustrating a graph of optical window luminous intensity versus viewing position on a window surface of a waveguide and a method of adjusting the light flux of a light source in an array in accordance with the present disclosure. FIG. 6 is a schematic diagram illustrating a graph of luminous flux distribution for an array of light sources and a method for adjusting the luminous flux of the light sources in the array relative to the waveguide, in accordance with the present disclosure. FIG. 6 is a schematic diagram illustrating a graph of optical window luminous intensity versus viewing position on a window surface of a waveguide and a method of adjusting the light flux of a light source in an array in accordance with the present disclosure. FIG. 6 is a schematic diagram illustrating a graph of luminous flux distribution for an array of light sources and a method for adjusting the luminous flux of the light sources in the array relative to the waveguide, in accordance with the present disclosure. FIG. 4 is a schematic diagram illustrating a graph of optical window intensity versus viewing position on a window surface and a method of adjusting the light flux of a light source in an array for the left and right eye illumination phases in accordance with the present disclosure. FIG. 6 is a schematic diagram illustrating a graph of optical window luminous intensity versus viewing position on a window surface of a waveguide and a method for adjusting a light flux of a light source in an array for an illumination phase of a right eye in accordance with the present disclosure. FIG. 6 is a schematic diagram illustrating a luminous flux distribution graph for an array of light sources for the left and right eye illumination phases and a method for adjusting the light flux of the light sources in the array relative to the waveguide for the right eye illumination phase according to the present disclosure; 4 is a schematic diagram illustrating a graph of optical window intensity versus viewing position on a waveguide window surface in accordance with the present disclosure. Fig. 6 is a schematic diagram illustrating a further graph of optical window intensity versus viewing position on a window surface of a waveguide, in accordance with the present disclosure. Fig. 6 is a schematic diagram illustrating a further graph of optical window intensity versus viewing position on a window surface of a waveguide, in accordance with the present disclosure. FIG. 6 is a schematic diagram illustrating a graph of luminous flux distribution for an array of light sources that corrects for light source efficiency degradation in accordance with the present disclosure. FIG. 1 is a schematic diagram illustrating a front view of a landscape mode directional display device in accordance with the present disclosure. 1 is a schematic diagram illustrating a front view of a portrait mode directional display device in accordance with the present disclosure. 28B is a schematic diagram illustrating a further graph of optical window intensity versus viewing position at the window face of the waveguide for the configuration of FIG. 27B, in accordance with the present disclosure. FIG. 6 is a schematic diagram illustrating a side view of a waveguide and viewing window for observer movement in accordance with the present disclosure. FIG. 29 is a schematic diagram illustrating a luminous flux distribution graph for an array of light sources and a method of adjusting the luminous flux of the light sources in the array relative to the waveguide with viewer motion of FIG. 28 in accordance with the present disclosure. FIG. 6 is a schematic diagram illustrating an array of viewing windows during an observer movement between viewing positions in accordance with the present disclosure. Fig. 6 is a schematic diagram showing the intensity distribution of an array of viewing windows according to the present disclosure. Fig. 6 is a schematic diagram illustrating a further intensity distribution of an array of viewing windows according to the present disclosure. Fig. 6 is a schematic diagram illustrating a further intensity distribution of an array of viewing windows according to the present disclosure. Fig. 6 is a schematic diagram illustrating a further intensity distribution of an array of viewing windows according to the present disclosure. FIG. 6 is a schematic diagram illustrating display illumination non-uniformity resulting from a non-uniform window intensity distribution in accordance with the present disclosure. 4 is a schematic diagram illustrating non-uniform light flux distribution from multiple light sources in accordance with the present disclosure. 4 is a schematic diagram illustrating non-uniform light flux distribution from multiple light sources in accordance with the present disclosure. 4 is a schematic diagram illustrating non-uniform light flux distribution from multiple light sources in accordance with the present disclosure. 4 is a schematic diagram illustrating non-uniform light flux distribution from multiple light sources in accordance with the present disclosure. 4 is a schematic diagram illustrating non-uniform light flux distribution from multiple light sources in accordance with the present disclosure. 4 is a schematic diagram illustrating non-uniform light flux distribution from multiple light sources in accordance with the present disclosure. 1 is a schematic diagram illustrating a landscape orientation 2D directional display in accordance with the present disclosure. 43 is a diagram illustrating a graph of scaled luminous flux versus light source position for the display of FIG. 42 in accordance with the present disclosure. 1 is a schematic diagram illustrating a vertically oriented 2D directional display in accordance with the present disclosure. 45 is a schematic diagram illustrating a scaled luminous flux graph versus light source position for the display of FIG. 44 in accordance with the present disclosure. 1 is a schematic diagram illustrating a control system and a front view of a directional backlight device according to the present disclosure. 1 is a schematic diagram illustrating a control system and a front view of a directional backlight device according to the present disclosure. 1 is a schematic diagram illustrating an apparatus for driving a light source for a calibration mode of operation in accordance with the present disclosure. FIG. 6 is a schematic diagram illustrating a light source array in a calibration mode of operation in accordance with the present disclosure. FIG. 6 is a schematic diagram illustrating a front view of a light source array arranged to implement color correction in accordance with the present disclosure. FIG. 6 is a schematic diagram illustrating a front view of a further light source array arranged to implement color correction in accordance with the present disclosure. 4 is a schematic diagram illustrating a chromaticity variation graph of an optical window and a method of correcting the chromaticity variation in accordance with the present disclosure. 1 is a schematic diagram illustrating a front view of a light source array in accordance with the present disclosure. 2 is a front view of a light source array and a schematic diagram illustrating a method of correcting a light source failure in accordance with the present disclosure.

  The time-division multiplexed autostereoscopic display uses light from all pixels of the spatial light modulator to the first field window in the first time slot and all pixels to the second field window in the second time slot. Orientation can advantageously improve the spatial resolution of the autostereoscopic display. Thus, an observer who is looking to receive light in the first and second viewing windows will see a full resolution image across the display from multiple time slots. A time-division multiplexed display comprises a substantially transparent time-division multiplexed spatial light modulator using directional optical elements, wherein the directional optical elements substantially form an image of the light illuminator array on the window surface. By orienting the light illuminator array through, directional illumination can be conveniently achieved.

  The uniformity of the viewing window can be conveniently independent of the arrangement of pixels in the spatial light modulator. Such a display can advantageously provide a low flicker observer tracking display with low crosstalk levels for observer movement.

  In order to achieve high uniformity on the window surface, it is desirable to provide an array of lighting elements that has high spatial uniformity. The light illuminator elements of the time series illumination system can be provided, for example, by spatial light modulator pixels of a size of about 100 micrometers combined with a lens array. However, such pixels have the same problems as spatially multiplexed displays. In addition, such devices are less efficient and costly and may require additional display components.

  High window uniformity can be conveniently achieved with a macroscopic light illuminator, such as, for example, an array of LEDs typically combined with homogenizing and diffusing optics that are typically 1 mm or larger in size. However, increasing the size of the light illuminator element means that the size of the directional optical element increases proportionally. For example, a 16 mm wide light illuminator that forms an image on a 65 mm wide viewing window may require a rear working distance of 200 mm. Thus, increasing the thickness of the optical element may hinder beneficial applications, such as for mobile displays or large area displays.

  In response to the aforementioned drawbacks, optical valves such as those described in commonly-owned US patent application Ser. No. 13 / 300,293, simultaneously provide high resolution images with flicker-free observer tracking and low crosstalk levels. Can be conveniently arranged in combination with a fast-switching transmissive spatial light modulator to achieve time-division multiplexed autostereoscopic illumination in a thin package. A one-dimensional array of viewing positions or windows is described, which can display different images, usually in a first horizontal direction, but usually contains the same image when moving in a second vertical direction.

  Conventional non-imaging display backlights typically use optical waveguides and have edge illumination from multiple light sources such as LEDs. However, there are many fundamental differences in function, design, structure, and operation between such conventional non-imaging display backlights and the imaging directional backlights discussed in this disclosure. Should be recognized.

  In general, for example, in accordance with the present disclosure, an imaging directional backlight is configured to direct illumination from a plurality of light sources through the display panel to each of the plurality of optical windows in at least one axis. Is done. Each optical window is substantially formed as an image in at least one axis of the light source by the imaging system of the imaging directional backlight. An imaging system can be formed to image a plurality of light sources on each of the viewing windows. In this way, the light from each of the plurality of light sources is substantially invisible to the observer's eyes outside each of the viewing windows.

  In contrast, conventional non-imaging backlights or light guide plates (LGP) are used for illumination of 2D displays. See, for example, Kalil Kalantar et al. , Backlight Unit With Double Surface Light Emission, J.A. Soc. Inf. Display, Vol. 12, Issue 4, pp. 379-387 (Dec. 2004). Non-imaging backlights typically direct illumination from multiple light sources through the display panel into a substantially common viewing zone for each of the multiple light sources, providing a wide viewing angle and high display uniformity. It is configured to be realized. Thus, the non-imaging backlight does not form a viewing window. In this way, the light from each of the plurality of light sources can be seen by the viewer's eyes at substantially all positions across the viewing zone. Such conventional non-imaging backlights can be provided by brightness enhancement films such as 3M BEF ™, for example, with some directionality, such as increasing screen gain compared to Lambert illumination. Can have. However, such directivity can be substantially the same for each of the respective light sources. Therefore, it will be apparent to those skilled in the art that a conventional non-imaging backlight is different from an imaging directional backlight for the above reasons. Edge-lit non-imaging backlight illumination structures can be used in liquid crystal display systems such as those found in 2D laptops, monitors, and TVs. Light propagates from the end of a lossy waveguide, which can include sparse features, usually local notches, on the surface of the guide that cause the light to disappear regardless of the direction of light propagation. To do.

  As used herein, an optical valve is one of a light guide structure or light guide device, for example, called a light valve, an optical valve directional backlight, and a valve directional backlight (“v-DBL”). An optical structure that can be a seed. In the present disclosure, an optical valve is different from a spatial light modulator (although the spatial light modulator is also commonly referred to in the art as a “light valve”). One example of an imaging directional backlight is an optical valve that can use a collapsible optical system. The light can propagate through the optical valve in one direction with substantially no loss and can be incident on the imaging reflector, which is hereby incorporated by reference in its entirety. As described in US Pat. No. 300,293, light can be propagated in the opposite direction so that it can be extracted by multiple reflection off tilted light extraction features and directed to the viewing window.

  Examples of imaging directional backlights as used herein include stepped waveguide imaging directional backlights, folding imaging directional backlights, wedge-type directional backlights, or optical valves. Including.

  Further, as used herein, the stepped waveguide imaging directional backlight can be an optical valve. The stepped waveguide includes a waveguide for guiding light, and further includes a first light guide surface and a second light guide surface opposite the first light guide surface, the plurality of steps arranged as steps. The waveguide for an imaging directional backlight further includes a plurality of light guide mechanisms interspersed with the extraction mechanism.

  Further, as used, the folding imaging directional backlight can be at least one of a wedge-type directional backlight or an optical valve.

  In operation, light can propagate through the exemplary optical valve in a first direction from the input end to the reflection end and can be transmitted substantially without loss. Light can be reflected at the reflection end and propagates in a second direction substantially opposite the first direction. As the light propagates in the second direction, the light can be incident on a plurality of light extraction mechanisms operable to redirect the light out of the optical valve. That is, the optical valve generally allows light to propagate in the first direction and allows light to be extracted while propagating in the second direction.

  With the optical valve, time-series directional illumination in a large display area can be realized. Furthermore, an optical element thinner than the rear working distance of the optical element can be used to direct light from the macroscopic light irradiator to the nominal window surface. Such a display can use an array of light extraction mechanisms configured to extract light propagating in opposite directions into substantially parallel waveguides.

  The implementation of a thin imaging directional backlight for use with an LCD is by 3M, eg, US Pat. No. 7,528,893, by Microsoft, referred to herein as “Wedge Type Directional Backlight”, See, for example, U.S. Patent No. 7,970,246, by RealD, for example, U.S. Patent Application No. 13 / 300,293, referred to herein as "Optical Valve" or "Optical Valve Directional Backlight". All of which are incorporated herein by reference in their entirety.

  The present disclosure can include a first guide surface and a second guide surface, wherein the light includes a plurality of light extraction mechanisms and a plurality of intermediate regions, for example between the inner surfaces of a stepped waveguide. Provided is a stepped waveguide imaging directional backlight that can be reflected back and forth. Since the light travels along the length of the stepped waveguide, the light does not substantially change the angle of incidence relative to the first guide surface and the second guide surface, and the criticality of the medium at these inner surfaces. The corner cannot be reached. Light extraction is conveniently achieved by multiple light extraction mechanisms that can be multiple facets of a second guide surface (step ("riser")) that is inclined relative to multiple intermediate regions (step "tread") It should be noted that the multiple light extraction mechanisms can be configured to provide light extraction from the structure, although they cannot be part of the light guide operation of the stepped waveguide. In particular, a wedge-type imaging directional backlight can guide light into a wedge-shaped waveguide with a continuous inner surface, so a stepped waveguide (optical valve) That is, it is not a wedge type imaging directivity backlight.

  FIG. 1A is a schematic diagram illustrating a front view of light propagation in one embodiment of a directional display device, and FIG. 1B is a schematic diagram illustrating a side view of light propagation in the directional display device of FIG. 1A.

  FIG. 1A shows a front view in the xy plane of a directional backlight of a directional display device and includes a light illuminator array 15 that can be used to illuminate a stepped waveguide 1. The light irradiator array 15 includes light irradiator elements 15 a to 15 n (“n” is an integer greater than 1). In one example, the stepped waveguide 1 of FIG. 1A can be a stepped, display-sized waveguide 1. The plurality of light irradiator elements 15a to 15n are a plurality of light sources that can be a plurality of light emitting diodes (LEDs). An LED is described herein as a plurality of light emitter elements 15a-15n, but other, but not limited to, diode sources, semiconductor sources, laser sources, local field emission sources, organic emitter arrays, etc. Multiple light sources can be used. Further, FIG. 1B shows a side view in the xz plane, where the light illuminator array 15, SLM (spatial light modulator) 48, multiple extraction mechanisms 12, multiple intermediate regions 10, and stages arranged as shown. The attached waveguide 1 is included. The side view provided in FIG. 1B is an alternative view of the front view shown in FIG. 1A. 1A and 1B can correspond to each other, and the stepped waveguides 1 of FIGS. 1A and 1B can correspond to each other.

  Further, in FIG. 1B, the stepped waveguide 1 can have a thin input end 2 and a thick reflective end 4. Therefore, the waveguide 1 extends between the input end 2 that receives the input light and the reflection end 4 that reflects the input light and returns it through the waveguide 1. The lateral length across the waveguide at the input end 2 is greater than the height of the input end 2. The plurality of light irradiator elements 15 a to 15 n are arranged at different input positions in the lateral direction across the input end 2.

  The waveguide 1 extends between the input end 2 and the reflection end 4 and has a first guide surface and a first opposing guide for guiding light back and forth along the waveguide 1 by total internal reflection (TIR). 2 guide surfaces. The first guide surface is a plane. The second guide surface faces the reflective end 4 and causes at least some light directed back from the reflective end through the waveguide 1 to change the total internal reflection at the first guide surface and to the SLM 48. It has a plurality of light extraction mechanisms 12 that are tilted to reflect, for example, in a direction that allows output through the upper first guide surface in FIG. 1B.

  In this example, the multiple light extraction mechanisms 12 are multiple reflective facets even though other reflective mechanisms could be used. The plurality of light extraction mechanisms 12 do not guide light through the waveguide, whereas the plurality of intermediate regions on the second guide surface in the middle of the plurality of light extraction mechanisms 12 guide light without extraction. These regions of the second guide surface are planar and may extend parallel to the first guide surface or with a relatively low slope. The plurality of light extraction mechanisms 12 extend laterally in those regions so that the second guide surface can have a stepped shape including the plurality of light extraction mechanisms 12 and a plurality of intermediate regions. The plurality of light extraction mechanisms 12 are oriented to reflect light from the plurality of light sources through the first guide surface after reflection from the reflection end 4.

  The plurality of light extraction mechanisms 12 are configured to direct input light from different input positions in a lateral direction across the input ends in different directions relative to the first guide surface determined by the input positions. Since the plurality of illumination elements 15a to 15n are arranged at different input positions, the light from each of the illumination elements 15a to 15n is reflected in the different directions. In this way, each illumination element 15a-15n directs light to each of the optical windows in the output direction distributed laterally according to the input position. The transverse direction over the input end 2 where the input positions are distributed corresponds to the output light, transverse to the normal to the first guide surface. In this embodiment in which the deflection at the reflecting end 4 and the first guide surface is generally orthogonal to the lateral direction, the lateral direction as defined at the input end 2 and with respect to the output light is parallel. Maintained. Under control of the control system, the plurality of light illuminator elements 15a-15n can be selectively manipulated to direct light into a selectable optical window. Multiple optical windows may be used individually or in groups as a viewing window.

  In the present disclosure, an optical window can correspond to a single light source image on a window surface, which is a nominal surface, that a plurality of optical windows form throughout the display device. Alternatively, the optical window can correspond to an image of a group of light sources projected together. Such a light source group can advantageously improve the uniformity of the optical window of the array 121.

  By way of comparison, a viewing window is an area in the window surface where light is provided that contains image data of substantially the same image from the display area. Thus, the viewing window can be formed from a single optical window or multiple optical windows under the control of the control system.

  The SLM 48 extending across the waveguide is transmissive and modulates light passing therethrough. The SLM 48 can be a liquid crystal display (LCD), but this is merely an example, and other spatial light modulators or displays, including LCOS, DLP devices, etc. Can be used to reflect and operate. In this example, the SLM 48 is disposed across the first guide surface of the waveguide and modulates the light output through the first guide surface after reflection from the plurality of light extraction mechanisms 12.

  The operation of a directional display device that can provide a one-dimensional array of optical windows is shown in the front view of FIG. 1A, and a side view is outlined in FIG. 1B. 1A and 1B, in operation, light is an array of light illuminator elements 15a-15n located at different positions, y, along the surface of the input end 2, x = 0, of the stepped waveguide 1. The light is emitted from the light irradiator array 15. The light can propagate in the stepped waveguide 1 along + x in the first direction, and at the same time, the light can be developed in a fan shape on the xy plane, and has a positive power in the lateral direction. Upon reaching the curved reflecting end 4, it can fill the curved end side 4 approximately or completely. During propagation, light can spread at a set of angles below the critical angle of the guide material in the xz plane. The plurality of extraction mechanisms 12 linking the plurality of intermediate regions 10 of the second guide surface of the stepped waveguide 1 can have a tilt angle that exceeds a critical angle, and thus along + x in the first direction It can be ruled out by substantially all light propagating, ensuring forward propagation with virtually no loss.

  Continuing with the discussion of FIGS. 1A and 1B, the reflective end 4 of the stepped waveguide 1 can usually be made reflective by coating with a reflective material such as silver, but other reflective techniques can also be used. Can do. Thereby, the light can be redirected in the second direction, return to the guide in the -x direction, and can be substantially focused on xy or the display surface. Angular diffusion is substantially maintained with respect to the main propagation direction in the xz plane, so that light can hit the end of the riser and be reflected out of the guide. In one embodiment with multiple tilt extraction mechanisms 12 of about 45 degrees, the light is effective to approximate normal to the xy display surface, with xz angular diffusion maintained substantially relative to the propagation direction. Can be oriented. This angular diffusion may increase as light exits the stepped waveguide 1 due to refraction, and may decrease somewhat due to the reflective nature of the multiple extraction mechanisms 12.

  In some embodiments involving multiple uncoated extraction features 12, reflections may be reduced due to lack of total internal reflection (TIR), narrowing the xz angle profile and causing deviation from normal. There is. However, in other embodiments with silver-coated or metal-coated extraction mechanisms, increased angular diffusion and central normal direction can be retained. Continuing with the description of the embodiment with the silver coating extraction mechanism, in the xz plane, light can be approximately focused out of the stepped waveguide 1 and from the center of the input edge into the light illuminator array 15. The light irradiator elements 15a to 15n can be oriented so as to be shifted from the normal line in proportion to the y position. By having independent light illuminator elements 15a-15n along the input end 2, light can be emitted from the entire first guide surface 6 and can propagate to different outer angles as shown in FIG. 1A. .

  Illuminating a spatial light modulator (SLM) 48, such as a high-speed liquid crystal display (LCD) panel with such a device, the plan view or the yz plane viewed from the end of the light illuminator array 15 in FIG. 2A, FIG. As shown in FIG. 2C and a side view in FIG. 2C, an autostereoscopic 3D can be realized. 2A is a schematic diagram showing the propagation of light in a directional display device in plan view, and FIG. 2B is a schematic diagram showing the propagation of light in a directional display device in front view, and FIG. Fig. 4 is a schematic diagram showing the propagation of light in a directional display device in a side view. As shown in FIGS. 2A, 2B, and 2C, the stepped waveguide 1 can be located behind a high-speed (eg, greater than 100 Hz) LCD panel SLM 48 that displays continuous right-eye and left-eye images. Synchronously, certain light emitter elements 15a-15n ("n" is an integer greater than 1) of the light emitter array 15 can be selectively turned on and off, and the directionality of the system Provides illumination light that enters the right and left eyes substantially independently. In the simplest case, each set of illuminator elements of the illuminator array 15 is turned on together, a one-dimensional viewing window 26 where both eyes that are horizontally separated can see the left eye image, or Although the width in the horizontal direction is limited, the optical pupil extends in the vertical direction, and another viewing window 44 that can mainly view the right eye image by both eyes and a central position where both eyes can see different images. I will provide a. The field window 26 can include an array of optical windows 260 and the field window 44 can include an array of optical windows 440, each of which is formed by a single light illuminator of the array 15. The Accordingly, the viewing windows 26 and 44 can be formed by arranging a plurality of light irradiators. In FIG. 2A, the viewing window 26 is shown as being formed by a single light irradiator 15a, and thus can include a single optical window 260. Similarly, the viewing window 44 is shown as being formed by a single light irradiator 15n, and thus can include a single optical window 440. In this way, 3D can be viewed when the viewer's head is aligned approximately in the center. Movement away from the center position to the side can shrink the scene into a 2D image.

  The reflective end 4 can have a positive lateral power across the waveguide. In an embodiment in which the reflective end 4 normally has a positive refractive power, the optical axis is a line that passes through the center of curvature of the reflective end 4, for example, and coincides with the axis of mirror symmetry of the end 4 about the x axis. It can be defined with reference to the shape of the reflection end 4 such as. If the reflective surface 4 is a plane, the optical axis should be defined similarly with respect to other components having refractive power, such as a plurality of light extraction functions 12, or a Fresnel lens 62 described below, for example, if curved. Can do. The optical axis 238 usually coincides with the mechanical axis of the waveguide 1. In this embodiment, which typically includes a substantially cylindrical reflective surface at the end 4, the optical axis 238 passes through the center of curvature of the surface of the end 4 and mirrors the side 4 about the x axis. A line that coincides with the axis of symmetry. The optical axis 238 usually coincides with the mechanical axis of the waveguide 1. The cylindrical reflecting surface at the end 4 may typically have a spherical outer shape, optimizing the ability for on-axis and off-axis viewing positions. Other profiles can also be used.

  FIG. 3 is a schematic diagram showing a directional display device in a side view. Furthermore, FIG. 3 shows in more detail a side view of the operation of the stepped waveguide 1 which can be a transmissive material. The stepped waveguide 1 includes a light irradiator input end 2, a reflection end 4, a first guide surface 6 that may be substantially planar, a plurality of intermediate regions 10 and a plurality of light extraction mechanisms 12. A second guide surface 8 comprising. In operation, the light beam 16 from the light emitter element 15c of the light emitter array 15 (not shown in FIG. 3), which may be an addressable array of LEDs, for example, is due to the first guide surface 6. The total internal reflection and total internal reflection by the plurality of intermediate regions 10 of the second guide surface 8 can lead to the reflection end 4, which may be a mirror surface, in the stepped waveguide 1. The reflection end 4 may be a mirror surface and may reflect light, but in some embodiments, light may pass through the reflection end 4.

  Continuing the discussion of FIG. 3, the light beam 18 reflected at the reflection end 4 is further guided into the stepped waveguide 1 by total internal reflection at the reflection end 4, and can be reflected by a plurality of extraction mechanisms 12. . Light rays 18 incident on the plurality of extraction mechanisms 12 can be substantially deflected from the light guide mode of the stepped waveguide 1 and automatically pass through the first guide surface 6 as indicated by the light rays 20. The viewing window 26 of the stereoscopic display can be oriented to an optical pupil that can be formed. The width of the field window 26 can be determined by at least the size of the light irradiator in the reflection end 4 and the plurality of extraction mechanisms 12, the number of light irradiator elements 15n irradiated, the output design distance, and the refractive power. The height of the field window can be mainly determined by the reflection cone angle of the plurality of extraction mechanisms 12 and the illumination cone angle input at the input end 2. Thus, each field window 26 represents a range of individual output directions relative to the surface normal direction of the spatial light modulator 48 that intersects the window surface 106 at a nominal visual distance.

  FIG. 4A is a schematic diagram illustrating a front view of a directional display device illuminated by a first light illuminator element that includes a plurality of curved light extraction mechanisms. Further, FIG. 4A shows in a front view the further guidance of the light rays from the light emitter elements 15 c of the light emitter array 15 to the stepped waveguide 1 having the optical axis 28. In FIG. 4A, the directional backlight may include a stepped waveguide 1 and a light source light irradiator array 15. Each of the output rays is directed from the respective input end 2 of the light irradiator 15c toward the same optical window 260. 4A can be emitted from the reflection end 4 of the stepped waveguide 1. As shown in FIG. 4A, the light beam 16 can be oriented from the light irradiator element 15 c toward the reflection end 4. Next, the light beam 18 can be reflected from the light extraction mechanism 12 and emitted from the reflection end 4 toward the optical window 260. Thus, the ray 30 can intersect the ray 20 in the optical window 260 or have a different height in the viewing window as indicated by the ray 32. In addition, in various embodiments, the sides 22 and 24 of the waveguide 1 can be transmission surfaces, mirror surfaces, or blackened surfaces. Continuing with the discussion of FIG. 4A, the plurality of light extraction mechanisms 12 can be extended and the first of the second guide surface 8 (shown in FIG. 3 but not shown in FIG. 4A). The direction of the plurality of light extraction mechanisms 12 in the region 34 may be different from the direction of the plurality of light extraction mechanisms 12 in the second region 36 of the second guide surface 8. Similar to other embodiments discussed herein, for example, as shown in FIG. 3, the plurality of light extraction mechanisms of FIG. 4A may alternate with a plurality of intermediate regions 10. As shown in FIG. 4A, the stepped waveguide 1 can include a reflective surface on the reflective end 4. In one embodiment, the reflective end of the stepped waveguide 1 can have a positive lateral power across the stepped waveguide 1.

  In another embodiment, each of the plurality of light extraction features 12 of the directional backlight can have a lateral positive refractive power across the waveguide.

  In another embodiment, each of the directional backlights can include a plurality of light extraction features 12 that can be a plurality of facets of the second guide surface. The second guide surface can have regions alternating with a plurality of facets that may be configured to direct the light through the waveguide without substantially extracting the light.

  FIG. 4B is a schematic diagram illustrating a front view of a directional display device that can be illuminated by a second light illuminator element. Furthermore, FIG. 4B shows the light rays 40, 42 from the second light emitter element 15h of the light emitter array 15. FIG. The curvature of the reflective surface on the reflective end 4 and the plurality of light extraction mechanisms 12 is generated in cooperation with a second optical window 440 that is laterally separated from the optical window 260 by light rays from the light illuminator element 15h. To do.

  The configuration shown in FIG. 4B cooperates with the refractive power at the reflective end 4 and the refractive power that can arise from different orientations of the multiple extended light extraction mechanisms 12 between regions 34 and 36, as shown in FIG. 4A. A real image of the light irradiator element 15c can be conveniently provided in the optical window 260, which can form a real image by action. With the configuration of FIG. 4B, it is possible to improve the aberration of imaging of the light irradiator element 15 c at the lateral position in the optical window 260. By improving the aberration, it is possible to extend the visual freedom for the autostereoscopic display while realizing a low crosstalk level.

  FIG. 5 is a schematic diagram illustrating a front view of one embodiment of a directional display device having a substantial plurality of linear light extraction mechanisms. Further, FIG. 5 is similar to FIG. 1 (with similar corresponding elements) with one of the differences that the light extraction mechanisms 12 are substantially straight and parallel to each other. The configuration is shown. Such an arrangement can advantageously provide substantially uniform illumination across the display surface and is more convenient to manufacture than the multiple curve extraction mechanisms of FIGS. 4A and 4B. The optical axis 321 of the directional waveguide 1 may be the optical axis direction of the surface at the reflection end 4. The refractive power of the reflection end 4 is configured to cross the optical axis direction, so that the light beam incident on the reflection end 4 has an angular deflection that varies due to the lateral offset 319 of the incident light beam from the optical axis 321. Become.

  FIG. 6A is a schematic diagram illustrating one embodiment of generating a first viewing window in a time division multiplexed imaging directional display device in a first time slot, and FIG. 6B is a time in a second time slot. FIG. 6C is a schematic diagram illustrating another embodiment of generating a second field window in a division multiplexed imaging directional backlight device, and FIG. 6C illustrates a first field in a time division multiplexed imaging directional display device. 6 is a schematic diagram illustrating another embodiment of generating a window and a second viewing window. Furthermore, FIG. 6A schematically illustrates the generation of a viewing window 26 from the stepped waveguide 1. The light emitter element group 31 in the light emitter array 15 may provide a light cone 17 that is oriented toward the field window 26 (which may include a single optical window 260 or an array of optical windows 260). FIG. 6B schematically illustrates the generation of the viewing window 44. The light emitter element group 33 in the light emitter array 15 may provide a light cone 19 that is oriented toward a field window 44 (which may include a single optical window 440 or an array of optical windows 440). In cooperation with the time division multiplexed display, the viewing windows 26 and 44 can be provided in the order shown in FIG. 6C. When an image on the spatial light modulator 48 (not shown in FIGS. 6A, 6B, and 6C) is adjusted according to the light direction output, an autostereoscopic image can be realized for a suitably arranged viewer. it can. Similar operations can be achieved with all imaging directional backlights described herein. Note that light illuminator element groups 31, 33 each include one or more illumination elements from illumination elements 15a-15n (where "n" is an integer greater than 1).

  FIG. 7 is a schematic diagram illustrating one embodiment of an observer tracking autostereoscopic display device including a time division multiplexed directional display device. As shown in FIG. 7, the directivity of the viewing windows 26 and 44 can be controlled by selectively turning on and off the light irradiator elements 15 a to 15 n along the axis 29. The position of the head 45 can be monitored using a camera, motion sensor, motion detector, or any other suitable optical, mechanical, or electrical means, and a plurality of suitable light emitter array 15 Regardless of the position of the head 45, a simple light illuminator element can be turned on and off to provide a substantially independent image for each eye. The head tracking system (or the second head tracking system) can provide more than one monitoring of the head 45, 47 (head 47 not shown in FIG. 7) and the same left eye Images and right-eye images can be supplied to the left and right eyes of each viewer to provide 3D to all viewers. Again, similar operations can be achieved with all imaging directional backlights described herein.

  FIG. 8 is a schematic diagram illustrating one embodiment of a multi-viewer directional display device as an example that includes an imaging directional backlight. As shown in FIG. 8, at least two 2D images can be oriented toward a pair of viewers 45, 47 so that each viewer sees a different image on the spatial light modulator 48. be able to. The two 2D images of FIG. 8 are similar to the description with respect to FIG. 7, where the two images are displayed sequentially and synchronously with a plurality of light sources having light directed towards two viewers. Can be generated. One image is presented on the spatial light modulator 48 in the first phase, and the second image is presented on the spatial light modulator 48 in a second phase that is different from the first phase. Corresponding to the first and second phases, the output illumination is adjusted to provide a first field window 26 and a second field window 44, respectively. An observer whose eyes are in the viewing window 26 recognizes the first image, and an observer whose eyes are in the viewing window 44 simultaneously recognizes the second image.

  FIG. 9 is a schematic diagram illustrating a privacy directional display device including an imaging directional backlight. The 2D display system can also use directional backlighting, which can primarily direct light to both eyes of the first viewer 45 as shown in FIG. 9, for safety and efficiency purposes. Further, as shown in FIG. 9, the first viewer 45 can see an image of the device 50, but the light is not directed towards the second viewer 47. Accordingly, the second viewer 47 is prevented from viewing the image on the device 50. Each embodiment of the present disclosure may advantageously provide an autostereoscopic function, a dual image function, or a privacy display function.

  FIG. 10 is a schematic diagram illustrating, in a side view, the structure of a time division multiplexed directional display device as an example including an imaging directional backlight. In addition, FIG. 10 includes a stepped waveguide 1 configured to provide a viewing window 26 for a substantially focused output across the output surface of the stepped waveguide 1, and a Fresnel lens 62. Fig. 2 shows a side view of an autostereoscopic display device that can be used. The vertical diffuser 68 extends in the vertical direction (parallel to the X axis) while further extending the height of the viewing window 26 and minimizing the blur in the horizontal direction (y axis). Can be arranged to achieve blur. The light can then be imaged through the spatial light modulator 48. The light illuminator array 15 may include a plurality of light emitting diodes (LEDs), which may be, for example, phosphor-converted blue LEDs or individual RGB LEDs. Alternatively, the light illuminator elements in the light illuminator array 15 may include a uniform light source configured to provide separate illumination areas and a spatial light modulator. Alternatively, the light illuminator element may include laser light source (s). The laser output can be directed onto the diffuser using means of scanning, for example using a galvanometer scanner or a MEMS scanner. Thus, in one example, laser light is used to provide a substantially uniform light source with a suitable output angle, and to reduce speckle, a plurality of suitable light emitter arrays 15 A light illuminator element can be provided. Alternatively, the light emitter array 15 can be an array of laser light emitting elements. In addition, in one example, the diffuser may be a wavelength converting phosphor so that illumination can be at different wavelengths up to visible output light.

  Accordingly, FIGS. 1-10 illustrate various waveguides 1, directional backlights including such waveguides 1 and light emitter arrays 15, and directional display devices including such directional backlights and SLMs 48. Explained. The various mechanisms disclosed above with reference to FIGS. 1-10 can be combined in any combination.

  FIG. 11 is a schematic diagram showing a front view of another imaging directional backlight shown as a wedge-type directional backlight, and FIG. 12 is a schematic diagram showing a side view of a similar wedge-type directional display device. . Wedge-type directional backlights are generally discussed in US Pat. No. 7,660,047, entitled “Flat Panel Lens”, which is incorporated herein by reference in its entirety. The structure includes a wedge-type waveguide 1104 having a bottom surface that can be preferentially coated with a reflective layer 1106 and an end corrugated surface 1102 that can also be preferentially coated with a reflective layer 1106. it can.

  In one embodiment, the directional display device reflects light from an input end, opposing first and second guide surfaces for directing light along the waveguide, and input light. A waveguide having a reflective end opposite the input end for returning through the waveguide may be included. A directional display device may include an array of light sources arranged at different input locations across the input end of the waveguide. The waveguide passes through the first guide surface with input light from a plurality of light sources as output light after reflection from the reflection end in the output direction with respect to the normal to the first guide surface, which can be mainly determined by the input position. And may be configured to be oriented in a plurality of optical windows. The directional display device is also configured to receive output light from the first guide surface and configured to modulate a first polarization component of the output light having a first polarization. A type spatial light modulator may be included.

  In one embodiment of a wedge-type directional backlight, the first guide surface may be configured to direct light by total internal reflection, the second guide surface is substantially planar, The light may be inclined at an angle that reflects light in a direction that changes total internal reflection for outputting light through the guide surface. The wedge type directional backlight may be part of a directional display device. The directional display device may also include a deflecting element that extends across the first guide surface of the waveguide for deflecting light toward a normal to the spatial light modulator.

  As shown in FIG. 12, light can enter the wedge-type waveguide 1104 from a plurality of local light sources 1101, and the light can propagate in a first direction before reflecting off the end face. Light can exit the wedge-type waveguide 1104 while on its return and illuminate the display panel 1110. As compared with the optical valve, the wedge-type waveguide can perform extraction with a taper that reduces the incident angle of propagating light so that light can escape when it is incident on the output surface at a critical angle. Light that escapes at a critical angle in a wedge-type waveguide propagates substantially parallel to the surface until it is deflected by a reorientation layer 1108 such as a prism array. Errors or dust on the output surface of the wedge-type waveguide can change the critical angle and can cause stray light and uniformity errors. Furthermore, an imaging directional backlight that uses a mirror to fold the beam path into a wedge-type directional backlight can use a facet mirror that biases the wedge-type waveguide in the light cone direction. Such facet mirrors are generally complex to manufacture and may result in illumination uniformity errors as well as stray light.

  Wedge-type directional backlights and optical valves further process the light beam in different ways. In wedge-type waveguides, light input at the appropriate angle is output at a defined position on the major surface, but the light beam is emitted at substantially the same angle and substantially parallel to the major surface. Let's go. In comparison, the light input at a specific angle to the stepped waveguide of the optical valve is output at an output angle determined by the input angle from a point over the first side. Conveniently, the stepped waveguide of the optical valve does not require an additional light redirecting film that extracts light toward the viewer, and input angle non-uniformity does not make it non-uniform across the display surface. .

  However, in the present disclosure, a wedge-type waveguide such as the wedge-type waveguide 1104 can usually be used for a directional backlight, and the stepped waveguide 1 is formed with various structures and the structures shown in FIGS. It can be replaced with the structure described below.

  Subsequently, several directional display devices are described that include a directional display device and a control system that includes a directional backlight, the directional display device including a waveguide and an SLM. In the following description, the waveguide, the directional backlight, and the directional display device are based on the structures of FIGS. 1 to 10 described above, and include them. As described above, the stepped waveguide 1 The same applies if the is replaced by a wedge type waveguide. Except for the modifications and / or additional features described below, the above description applies equally to the following waveguides, directional backlights, and display devices, but will not be repeated for the sake of brevity.

  FIG. 13 is a schematic diagram illustrating a directional display device that includes a display device 100 and a control system. The configuration and operation of the control system are described below, can be modified as needed, and can be applied to each display device disclosed herein.

  The directional display device 100 includes a directional backlight including the waveguide 1 and the array 15 of light illuminator elements 15n arranged as described above. The control system is configured to selectively manipulate the lighting elements 15a-15n to direct light into a plurality of selectable optical windows.

  The waveguide 1 is configured as described above. The reflection end 4 converges the reflected light. The Fresnel lens 62 can be configured to cooperate with the reflecting end 4, and realizes a plurality of field windows 26 on the window surface 106 observed by the observer 99. The transmissive spatial light modulator (SLM) 48 can be configured to receive light from a directional backlight. In addition, a diffuser 68 is provided to substantially eliminate moire interference between the waveguide 1 and the SLM 48 and Fresnel lens 62 pixels.

  The control system can include a sensor system configured to detect the position of the viewer 99 relative to the display device 100. The sensor system includes a head position measurement system 72 that can include a position sensor 70 such as a camera and a computer vision image processing system, for example. The control system further includes an illumination controller 74 to which the detection position of the observer supplied from the head position measurement system 72 is supplied to both, and an image controller 76. The illumination controller 74 supplies a drive signal to the light irradiator element 15n. By controlling the drive signal, the illumination controller 74 selectively manipulates the light illuminator element 15n and cooperates with the waveguide 1 to direct light into the viewing window 26. The illumination controller 74 selects the light illuminator element 15 that is manipulated according to the position of the observer detected by the head position measurement system 72, so that the field window 26 through which the light is directed is the left and right of the observer 99. Come to the position corresponding to the eye. Thus, the horizontal output directionality of the waveguide 1 corresponds to the position of the observer.

  The illumination controller 74 is configured to control the luminous flux of light emitted from each of the light sources of the array 15, which can be referred to as light gradation, by varying the drive signal supplied to each of the light irradiator elements 15. be able to. The luminous flux of the light source is a measure of the refractive power emitted by the light source and is measured in lumens.

  Control of the luminous flux is not limited and includes any of voltage modulation, current modulation, pulse width modulation, control of a spatial light modulator provided between the light source and the input end 2, or any other known gradation drive system This can be brought about by a suitable driving method. Furthermore, one or two light fluxes emitted from each of the light irradiator elements 15n are used to change the current flowing to each of the addressable devices or to change the brightness recognized by the observer by the afterimage. The above pulse length can be changed by a pulse width modulation method for changing the length. It is also possible to realize desired brightness control by combining these two effects.

  The image controller 76 controls the SLM 48 to display an image. In order to provide an autostereoscopic display, the image controller 76 and the illumination controller 74 can operate as follows. The image controller 76 controls the SLM 48 and displays the temporarily multiplexed left eye image and right eye image. The illumination controller 74 operates the plurality of light sources 15 and directs light to the plurality of viewing windows at positions corresponding to the left and right eyes of the observer in synchronization with the display of the left eye image and the right eye image. The position of the plurality of viewing windows can be mainly determined by the detected position of the observer. In this way, the autostereoscopic effect is realized using a time division multiplexing technique.

  As described below, the light flux controller 580 operating under user or automatic control controls the illumination controller 74 to scale inversely by the width associated with each of the lateral light illuminator elements 15n. Thus, a method of controlling the light irradiator element 15n of the directional backlight to output light having a light flux that fluctuates across the array 15 of light irradiator elements can be implemented.

  The amount of light flux that varies across the array 15 is the scaled light flux of the individual light irradiators 15. The scaling is the reverse, and its width is associated with each of the lateral light illuminator elements 15n. The purpose of the scaling is to take into account any variation in the pitch of the light emitter elements 15 across the array 15. Therefore, in the simple case where the light illuminator elements 15n are arranged at different input positions at a constant lateral pitch across the input end 4 of the waveguide 1, the scaling is constant, so the scaled luminous flux Is simply the actual light flux of the plurality of light emitter elements 15n. If the pitch of the lateral light illuminator elements 15n is variable, the scaled luminous flux takes into account its varying pitch.

  Thus, the scaled luminous flux can take into account the deviation between the multiple light sources and the non-uniformity across the respective luminous flux of the output. Thus, the width associated with the light emitter element 15n can be interpreted as the pitch of the plurality of array light emitter elements 15n in the light emitter element 15n under consideration. Similarly, the width associated with the light emitter element 15n can be interpreted as the width between the midpoints of the gaps between the plurality of light emitter elements 15n. The scaled luminous flux will be further described with reference to FIG.

  Here, a scaled luminous flux is conceivable because, as will be further described below, in the display device 100, this amount affects the luminous intensity of the output light. The luminous intensity of a display device is a measure of the force that the display device emits in a particular direction per unit solid angle. Thus, the scaled luminous flux is controlled to provide the desired luminous intensity.

  This is convenient, because the brightness of the display device 100 as perceived by the viewer 99 is derived by the brightness, which is a photometric measure of light intensity per unit area of light traveling in a given direction. . Therefore, the recognized brightness can be controlled by the variation of the luminous flux line density, for example, the brightness (luminance) recognized for different positions of the observer 99 can be varied and / or given. The power consumption can be minimized for the perceived brightness.

  The luminous flux considered is the total luminous flux emitted. This can be obtained by integrating the light beams emitted by the plurality of light irradiator elements 15 in a direction perpendicular to the lateral direction.

  In some embodiments, the light flux controller 580 can control the light flux to vary across an array of light illuminator elements 15n in a light flux distribution that is fixed relative to a lateral position.

  In other embodiments, the light flux controller 580 can control the light flux to vary across the array of light illuminator elements 15n according to the detected position of the observer 99 as detected by the sensor system.

  Several specific methods by which the light flux controller 580 controls the light flux to vary across the array of light illuminator elements 15n are described below.

  First, some embodiments will be described in which the luminous flux controller 580 can control the scaled luminous flux to vary across an array of light illuminator elements 15n in a luminous flux distribution fixed with respect to a lateral position. To do. This has certain advantages when the display device 100 is operated to display a 2D image viewable from a wide angle as compared to a directional operation mode such as an autostereoscopic mode. In that case, all the light irradiator elements 15n can be operated simultaneously, in which case the sensor system may not be used or may be omitted.

  Alternatively, the illumination controller 74 can operate the multiple light sources 15 to direct the light into a single viewing window that can be viewed with both eyes, according to the detected position of the viewer, It is configured to operate in a single phase for 2D viewing in privacy and high efficiency modes of operation. Such a viewing window is sufficiently wide to be seen by both the left and right eyes of the observer. Alternatively, a fixed luminous flux distribution may be applied when operating the display device to provide an autostereoscopic 3D display.

  FIG. 14A is a schematic diagram showing a plan view of a directional backlight including the waveguide 1 and an array of light illuminator elements 15n that provide an array of optical windows 260 on the window surface 106, the output direction, and thus The nominal lateral position of each window surface of the optical window 260 is determined by the respective lateral position of the light illuminator in the array 15. Thus, at an angle θ corresponding to a lateral (y-axis) position 262 across the window surface 106, the luminous intensity of the display seen from the plurality of optical windows 260 (as shown, right eye position 560 and left eye position 562). ) It may vary depending on the position of the observer 99. It is desirable to achieve a display light intensity variation that is Lambertian, so that the display appears equally bright to each eye of the viewer 99, that is, the brightness of the display is within the range of lateral visual freedom. Is substantially the same. Alternatively, it is desirable to realize a variation in display luminous intensity that lowers the brightness of the off-axis viewing position and realizes the power saving advantage.

  The movement function between each of the elements of the array 15 of the light irradiator elements 15n and each of the optical windows 260 of the array of optical windows is the scattering and diffusion of optical components provided between the array 15 and the window surface 106. , Diffraction, and imaging characteristics effects. Accordingly, the plurality of optical windows 260 is not a complete image of the plurality of light emitter elements 15n. However, the lateral position 262 of the plurality of optical windows 260 will generally be directly related to the lateral position 261 of the light emitter element 15n in the array 15.

  Thus, the light flux controller 580 can control the scaled light flux to vary the input position of the light illuminator element 15 laterally across the array of light illuminator elements 15n in the light flux distribution, thereby A desired light distribution that represents a change in the luminous intensity of the output light having an angle in the output direction is generated. An example thereof will be described below.

  FIG. 14B is a schematic diagram illustrating a graph of the luminous intensity 264 of the output light with respect to the viewing position 262 on the window surface 106 corresponding to the angle θ in the output direction. The light distribution 266 is Lambertian, and the observed brightness of the display is constant from the viewing position 500 to the viewing position 502 in the plurality of viewing windows, while the cosine of the viewing angle θ and thus the light intensity across the display varies. In that it has a varying luminous intensity.

In this embodiment, the Lambertian emitter achieves the same apparent brightness of the surface independent of the viewer's angle of view. Thus, the surface has isotropic brightness (measured in candela per meter ² or ² per lumen radian steradian per meter ² ), and variations in luminosity (measured in candela or rumen per steradian) 264 are ideal diffusions. The luminous intensity observed from the radiator follows Lambert's cosine law which is directly proportional to the cosine of the angle θ between the observer's line of sight and the surface normal. In this embodiment, Lambertian is used to describe the light emission of a display over a defined angular range, for example, the full width of a plurality of optical windows of the display. Thus, the light distribution can move in a non-Lambertian manner at positions on the window surface outside the width of the plurality of optical windows.

  Luminous intensity is typically considered in terms of points on the backlight, such as the point corresponding to the center of the SLM 48. The brightness of the display system (luminosity per unit area) can vary across the display area due to output non-uniformity and will vary further with each defined viewing angle of the unit area.

  FIG. 14B further illustrates the light distribution for light distribution 272 having a gain greater than one. More specifically, the light distribution 272 has a maximum luminous intensity corresponding to the maximum value of the luminous flux distribution, which is larger than the Lambertian light distribution 266, and the total power of the two light distributions 266 and the light distribution 272 is , The same for all of the output directions 500 to 502. Accordingly, the peak luminous intensity is greater at the on-axis position and decreases at a faster rate than the Lambertian light distribution 266. Accordingly, the display brightness is reduced at the off-axis viewing position. The ratio of the luminance of the light distribution 272 to the peak luminance of the light distribution 266 is often referred to as the display system gain.

  The light flux controller 580 controls the scaled light flux to provide output light with a light distribution 266 that is Lambertian or with a light distribution 272 that has a gain greater than 1, as follows: It can vary across an array of irradiator elements 15n.

  FIG. 15A is a schematic diagram illustrating the intensity of the output light relative to the viewing position 262 on the window surface 106 corresponding to the lateral angle θ in the output direction with respect to the optical axis 238 and a method for adjusting the scaled luminous flux of the array 15. is there. The light distribution 266 and the light distribution 272 are shown, but their peak intensities are matched so that the on-axis brightness is the same and the display appears equally bright for the on-axis viewing position.

  In one embodiment, a Lambertian light distribution 266 can be achieved by controlling all of the light emitter elements of the array 15 to have substantially the same scaled luminous flux output.

  In order to realize the light distribution 272, as indicated by the arrow 270, the light intensity at the off-axis position can be made lower than that of the light distribution 266. This can be achieved by controlling the scaled light flux of the multiple light illuminator elements to vary across the array 15 in the light flux distribution as follows.

  FIG. 15B is a schematic diagram illustrating a graph of the luminous flux distribution for an array of light illuminator elements and a method for adjusting the scaled luminous flux of the array 15. Therefore, the scaled beam 263 may be drawn relative to the lateral position 261 in the lateral direction across the input end 2 of the waveguide 1. In the construction of the waveguide 1 reflected by the plurality of light extraction mechanisms 12, the scaled light beam 263 has a constant light beam distribution 269 and provides a light distribution 266 that is Lambertian. Arrows 271 indicate a reduction in the scaled luminous flux for each of the light sources corresponding to arrow 270 at each of the optical window positions 262, as compared to a constant luminous flux distribution 269, and a light distribution 272 having a gain greater than 1. The provided non-linear luminous flux distribution 273 can be obtained. Therefore, the luminous flux distribution 273 has a maximum luminous flux value 508 and decreases on both sides of the maximum value 508. The maximum value 508 occurs for a plurality of light emitter elements that are aligned with the optical axis of the waveguide 1. In one embodiment, the light emitter elements of the array 15 are controlled so that the scaled light flux of the light emitter elements varies according to the non-linear light flux distribution 273, thereby having a gain greater than one. A display device 100 with a light distribution 272 is provided. That is, the luminous intensity 264 of the output light varies depending on the output direction angle 262 in the actual light distribution 272 that is larger than the Lambertian conceptual light distribution 266, and the total luminous intensity over all output directions is the same as the actual light distribution 272. The same.

  FIG. 15C is a schematic diagram showing details of FIG. 15B, but depicting the actual luminous flux 265 with the y-axis integrated over a direction perpendicular to the transverse direction. As described above, the actual light beam 265 at a given lateral position 261 over the input end 2 is integral of the light captured by the waveguide in an intercept perpendicular to the lateral direction, ie parallel to the z-axis. It is. Assuming that all light from each of the light sources is captured by waveguide 1, the actual beam 265 is the same as the output of the integrated bundle of light source intercepts in the z-axis. As shown in FIG. 15C with respect to detail 293 of FIG. 15B, the light sources of the array 15 are typically substantially non-uniform in the lateral direction (y-axis) due to the gap between the light sources and the structure within the light source. Have a good distribution. For example, as illustrated in FIGS. 50 and 51, the light source can include LEDs having blue and yellow light emitting areas. Lateral outputs of different actual luminous flux 265 and chromaticity when integrated over the thickness of the input end 2 can be realized in this way. For this purpose, a plurality of light sources can be arranged in stages, whereby the number of light sources 504 is related to a given light beam 506 that provides a scaled light beam with a light beam distribution 273. Thus, the luminous flux distribution 273 can be provided by the actual luminous flux 265 averaged over the lateral width associated with a single light illuminator element 15n. In operation, the light illuminator element 15n is not accurately imaged at the window surface 106, so that the plurality of viewing windows can include overlapping optical windows diffused laterally. Therefore, the conversion from the light flux distribution 273 to the light distribution 272 can further consider the blur between the plurality of adjacent optical windows 260 in the plurality of field windows 26 so as to realize a desired light distribution 262. Can be configured.

  Conveniently, the output brightness of the display can be maintained relative to the on-axis viewing position and can be reduced relative to the off-axis viewing position. Accordingly, the power consumption of the display can be reduced for a plurality of more inconvenient viewing positions, the display efficiency and the charging period can be improved, and the cost of the display can be reduced.

  FIG. 15D is a schematic diagram showing a graph of luminous flux distribution and a front view of a directional backlight aligned with the luminous flux distribution. For illustrative purposes, a flux distribution 273 of scaled beam 263 having a lateral position 261 is shown aligned with each of the light emitter elements of array 15. Thus, the light illuminator elements 514, 516 each have a scaled luminous flux 510, 512 that includes a maximum value 508 of the distribution 273 aligned with the optical axis 232 of the waveguide 1. The distribution 273 is provided between the position 261 at 501 and the position 261 at 503. Thus, the maximum value of the bundle distribution may be for a plurality of light irradiator elements aligned with the optical axis 232 of the waveguide. The maximum value of the bundle distribution may be for a plurality of light emitter elements 514, 516 aligned with the optical axis 232 of the waveguide 1. Conveniently, the peak luminous intensity of the output is provided on-axis with respect to the display normal 107 which can be aligned with the optical axis 232. Thus, the brightness is maximum for the on-axis position of the display having a gain greater than one. Since the on-axis position is usually the desired viewing position, especially for portable displays and the like, the display achieves a reduction in power consumption with respect to the off-axis viewing position, while at the best viewing conditions. Looks bright.

  The maximum value 508 of the luminous flux distribution relates to the light irradiator elements 514 and 516 aligned with the optical axis 232 of the waveguide 1. Such an arrangement can achieve a maximum value 259 of luminous intensity 264, which can be for each of the optical windows aligned with the optical axis 232 of the waveguide 1.

  The embodiment of FIG. 15D shows an array of light illuminator elements for wide-angle 2D viewing, ie multiple light illuminator elements can operate continuously or in a single phase, The light modulator 48 can include a single 2D image. Since all the light emitter elements 15n can be operated simultaneously, the sensor system may not be used or may be omitted. It would be further desirable to provide the benefit of increased display gain power savings in autostereoscopic mode for off-axis viewing positions.

  15E-15F are schematic diagrams illustrating luminous flux distribution graphs for an autostereoscopic Lambertian display system. In this case, the scaled beam fluctuates across an array of light illuminator elements 15n in a beam distribution fixed relative to the lateral position, but is temporarily multiplexed by manipulating the display device. The above-described autostereoscopic image is generated by light directed to a plurality of viewing windows at positions corresponding to the left and right eyes of the observer in synchronization with the display of the left and right eye images in synchronization with the display of the left and right eye images. A 3D display is provided.

  FIG. 15E shows an example in which a constant luminous flux distribution 269 is used to provide a light distribution 266 that is Lambertian, as shown in FIG. 14B. A plurality of viewing windows 26 can be formed from illumination of a plurality of light emitter elements in the subarray 520 for the left eye phase and the subarray 522 in the right eye phase. As the observer's 99 eyes move off-axis, the scaled luminous flux can have a constant value and the display can maintain a Lambertian appearance with viewing angle. Advantageously, the number of illuminated illuminator elements is significantly reduced compared to the arrangement of FIG. 15D. The brightness for each eye is substantially constant, reducing the appearance of depth errors in autostereoscopic viewing and increasing viewer comfort.

  FIGS. 15F and 15G illustrate an example of using a non-linear light flux distribution 273 to provide a light distribution 272 having a gain greater than one. Accordingly, a plurality of light illuminator elements can be controlled to output light having a scaled luminous flux 263 that varies across the plurality of light illuminator elements in accordance with the detected position of the observer 99. For example, FIG. 15F shows a case where the position detected by the observer is aligned with the optical axis, and FIG. 15F shows a case where the position detected by the observer is offset. The subarrays 520 and 522 of a plurality of light irradiator elements for the left and right eyes are selectively operated to change according to the detected position of the observer. The plurality of light illuminator element sub-arrays 520, 522 have a light intensity that varies across their width to obtain gain. Thus, the detected position of the observer 99 is controlled in such a way that a plurality of light irradiator elements are controlled to produce an output light intensity 264 that varies with the output light angle 262 in the light distribution 272 having a gain greater than one. Accordingly, light having a scaled luminous flux 263 that varies across a plurality of light emitter elements can be output. Conveniently, the power consumption of the array 15 of light emitter elements is reduced compared to the arrangement of FIG. 15E, since not all of the light emitter elements are operated at any given time.

  Conveniently, the power consumption of the off-axis can be reduced compared to the position of the on-axis, further reducing the power consumption.

  FIG. 15H is a schematic diagram illustrating a further graph of luminous flux distribution for an autostereoscopic display system having a gain greater than 1 and an off-axis viewing position. In this embodiment, the array of illuminator elements 520, 522 is arranged to track a distribution 273 indicated by matching the scaled beam at position 524, but the beam lines are equal across subarrays 520 and 522. Has a density. Thus, the scaled luminous flux is not fixed with respect to the lateral position of the plurality of light emitter elements, but over an array of light emitter elements 15n in the light flux distribution that varies according to the position detected by the observer. fluctuate. More particularly, this is controlled in such a way as to produce an output light intensity 264 that varies with the angle 262 of the detected position of the observer in the light distribution 272 having a gain greater than one.

  Accordingly, the left and right eye field windows are constituted by a distribution of luminous intensity 264, and substantially equal luminance can be realized for each eye in the form of a Lambertian distribution of luminous intensity. Again, not all of the light illuminator elements are operated at any given time, so the power consumption of the array 15 of light illuminator elements is reduced compared to the array of FIG. 15E. Off-axis power consumption can be reduced compared to on-axis position, each eye being substantially equal, reducing depth error in autostereoscopic viewing and increasing viewer comfort, Image brightness can be recognized.

  FIG. 16 is a schematic diagram illustrating a light emitter element addressing device. In this way, the illumination controller 74 can be configured to address the light emitter elements 243 of the array 15 by drive lines 244 that provide drive signals to the array of light emitter elements. As described elsewhere, at a position 261 across the array 15, the light illuminator element 243 may have a varying scaled flux. In operation, scaled luminous flux variations can be achieved by controlling the current entering each of the light sources 243 by the illumination controller 74 and the control system. For example, the light flux distribution can be controlled by current control or voltage control. Furthermore, the variation can be adjusted according to user requirements, so the user can select a high gain, low power consumption mode or a wide viewing mode.

  In this embodiment, the array 15 of light illuminator elements can be arranged, for example, at the input end 2 of the waveguide 1, as shown in FIG. 13, or as shown in FIG. 12, the wedge waveguide 1104. Input terminal 1103.

  FIG. 17 shows a further operation of the display device to provide an autostereoscopic 3D display, as described above, where the scaled luminous flux varies across the array of light illuminator elements 15n according to the detected position of the observer. In the example, it is a schematic diagram showing a graph of luminous intensity for each of an array of optical windows and an optical window. Thus, the light illuminator elements of the array 15 can provide a constant scaled luminous flux, and the optical system under such conditions can achieve a lambert property profile of luminous intensity at the window surface. Each of the light sources of the array 15 can be provided with an optical window 249 on the window surface 106. In the left and right eye illumination phases, the left eye viewing window 247 is provided by an array of left eye optical windows 530 and the right eye viewing window 251 is provided by an array of right eye optical windows 532, respectively. The left eye field window 247 and the right eye field window 251 are generated according to the detected position of the observer. The scaled light flux fluctuates across the array of light irradiator elements 15n according to the light flux distribution that generates the luminous intensity of the output light in a plurality of optical windows that fluctuate depending on the angle of the output direction in the light distribution 267. Thereby, the luminous intensity of the output light is generated in the field windows 247 and 251 in addition to the optical window arrays 530 and 532 that vary depending on the angle of the detected position of the observer in the horizontal direction in the light distribution 266. Therefore, the display device 100 can be realized with a substantially Lambertian output appearance. Accordingly, the light distributions 266, 267 can be Lambertian. In the embodiments described herein, a similar formation of a plurality of viewing windows is provided from a plurality of optical windows. By combining an array of optical windows 249, different light distributions to the viewing window 26 other than Lambertian are further provided.

  FIG. 18 is a schematic diagram illustrating a graph of optical window intensity 264 versus viewing position 262 for waveguide 1 that includes the uniform intensity of a plurality of light emitter elements in array 15 in another structure of waveguide 1. In the above embodiment, it is assumed that a substantially Lambertian light distribution 266 is realized for the light flux distribution 269. As described with reference to FIGS. 19A to 19B, in the embodiment of the waveguide 1, the waveguide 1 can exhibit a non-Lambertian operation. In particular, the light distribution 268 can be realized by the waveguide 1 including the horn type mechanisms 540 and 542. Thus, for a matched on-axis intensity 507, the off-axis intensity is substantially higher than that provided by the Lambertian output light emittance distribution 266, that is, the display brightness can be reduced to several off-axis viewing positions. Can be increased. When operating in 2D mode by correcting the light distribution 268, it is desirable to reduce the power consumption in the array 15 of light emitter elements.

  FIG. 19A is a schematic diagram showing a perspective view of light rays incident in a first direction toward the light extraction mechanism of the waveguide 1 of an alternative structure that reflects light by TIR, instead of the light extraction mechanism 12 not reflecting. . The surface 8 of the waveguide 1 can include a plurality of intermediate regions 10 and a plurality of light extraction mechanisms 12, sometimes referred to herein as a plurality of light extraction facets. An on-axis ray 300 parallel to the plurality of features 10 at an angle 307 to the normal 304 to the feature 12 is reflected by total internal reflection at the feature 12 along the ray 302. However, the light ray 301 remaining in the same xz plane as the light ray 300 at a smaller angle 307 with respect to the surface normal 304 of the plurality of mechanisms 12 can be transmitted to the light ray 305. Thus, the ray 305 can be lost from the output light distribution.

  FIG. 19B is a schematic diagram showing a perspective view of a light beam incident in a second direction on the light extraction mechanism of the waveguide 1 having the same structure as FIG. 19A. Off-axis rays 308 can be provided by the light emitter elements of the off-axis array 15 and are incident at an angle 308 on the on-axis rays in the xy plane. The ray 309 for on-axis incidence that would be transmitted by the mechanism 12 has a resolution angle greater than the angle 307 and thus is incident at an angle 312 with respect to the normal 304 that undergoes total internal reflection at the mechanism 12. Thus, ray 311 is reflected rather than transmitted. This means that the light flux of the output light reflected by the mechanism 12 varies as a part of the light flux of the input light with respect to the different light irradiator elements 15n. This contributes to an increase in luminous intensity 264 at each off-axis position 262 of the window surface, creating horn-type mechanisms 540, 542. The control system scales varying across the array of light emitter elements in a manner that controls the light emitter elements to compensate for this variation in the output light flux reflected by the facets, as follows: It is configured to output light having the light flux.

  FIG. 20A is a schematic diagram showing a graph of optical window intensity versus viewing position on the window face of the waveguide and a method for adjusting the scaled luminous flux of multiple light irradiator elements 15n. In order to achieve a light distribution 266 that is Lambertian, the light distribution can be modified as shown by arrows 270. This can be achieved by controlling the scaled light flux of the plurality of light illuminator elements 15n to vary across the array 15 in the light flux distribution as follows.

  FIG. 20B is a schematic diagram illustrating a graph of the luminous flux distribution for an array of light illuminator elements and a method for adjusting the scaled light flux of a plurality of light illuminator elements 15 n relative to the waveguide 1. Arrows 271 indicate a reduced scaled luminous flux compared to a constant luminous flux distribution 269 for each of the light sources corresponding to arrow 270 at each of the optical window positions 262 and provide a light distribution 266 that is Lambertian. Reaches a luminous flux distribution 277 of. Therefore, for each of the equivalent positions 262 and 261 and the luminous flux distribution 277, an arrow 271 that can have an equivalent length in proportion to the length of the arrow 270 can be provided. Thus, the luminous flux distribution 277 has a luminous flux maximum 508 and decreases on either side of the maximum 508 provided across the array 15. The maximum value 508 occurs for a plurality of light emitter elements that are aligned with the optical axis of the waveguide 1. The luminous flux distribution 277 also has “reverse horn type” mechanisms 544, 546 to correct the horn type mechanism in the light distribution 268.

  Further, in combination with the observer tracking configuration of FIG. 13, the light illuminator elements of the array 15 corresponding to the plurality of optical windows that are not visible to the observer 99 can be turned off, advantageously reducing power consumption, and thus The detection of the observer 99 in the form of controlling the light illuminator element to produce a luminous intensity 264 of the output light that varies with the angle 262 of the detected position of the observer 99 in the Lambertian light distribution 266. Light with a scaled luminous flux 263 that varies across multiple light illuminator elements can be output according to the determined position.

  Advantageously, the non-Lambertian luminous output of the waveguide 1 can be corrected to achieve a substantially uniform brightness across the viewing angle of the display.

  FIG. 21A is a schematic diagram illustrating a graph of optical window luminous intensity versus viewing position on a window surface of a waveguide and a method for adjusting the scaled luminous flux of multiple light irradiator elements 15n. In another embodiment, the light distribution 268 can be adjusted to achieve a light distribution 272 having a gain greater than one. More specifically, the light distribution can be corrected as indicated by arrow 270. This can be achieved by controlling the scaled light flux of the multiple light illuminator elements to vary across the array 15 in the light flux distribution as follows.

  FIG. 21B is a schematic diagram illustrating a graph of luminous flux distribution for an array of light illuminator elements and a method for adjusting the scaled light flux of a plurality of light illuminator elements 15 n relative to waveguide 1. Therefore, the light flux distribution 275 can be realized in the same manner as described with reference to FIG. 20B. Arrows 271 indicate a reduction in the scaled luminous flux for each of the light sources corresponding to arrow 270 at each of the optical window positions 262, as compared to a constant luminous flux distribution 269, and a light distribution 272 having a gain greater than 1. The resulting non-linear luminous flux distribution 275 is reached. Thus, the luminous flux distribution 275 has a scaled luminous flux maximum 508 and decreases on either side of the maximum 508 provided across the array 15. The maximum value 508 occurs for a plurality of light emitter elements that are aligned with the optical axis of the waveguide 1. The luminous flux distribution 277 also has “reverse horn type” mechanisms 544, 546 to correct the horn type mechanism in the light distribution 268.

  Furthermore, the array 15 can include a light flux distribution for a constant drive current that varies as the distribution 550 indicates. With knowledge of the distribution 550 before applying the correction indicated by the arrow 271, such variations can be removed while correcting the scaled light flux described by the non-linear light flux distribution 275. Thus, the total luminous intensity under curve 272 may be the same as the total luminous intensity under curve 266.

  In one embodiment, the light emitter elements of the array 15 are controlled so that the scaled light flux of the light emitter elements varies according to the non-linear light flux distribution 273, thereby having a gain greater than one. A display device 100 with a light distribution 272 is provided. That is, the luminous intensity 264 of the output light varies depending on the output direction angle 262 in the actual light distribution 272 that is larger than the Lambertian conceptual light distribution 266, and the total luminous intensity over all output directions is the same as the actual light distribution 272. The same.

  In an exemplary embodiment, 86 light emitter elements each capable of achieving a CW mode light output of 16 lumens per steradian in a Lambertian distribution of light emitter elements arranged in air. A 15.6 "spatial light modulator can be illuminated by the waveguide 1 including the array 15. When a luminous flux distribution 269 is provided, each such light emitter element is 350 mW. To achieve a total array power consumption of 30 W. For the same on-axis luminosity (and hence brightness), and for the light distribution 272 to luminosity and therefore to a luminous flux distribution similar to distribution 275 To reduce the total power consumption of the array 15 to 16 W. In the autostereoscopic operation mode, for example, a usage rate of 25%, When the plurality of light irradiator elements are operated in a pulse mode with a current overdrive of 50%, the plurality of light irradiator elements may have a total luminance of substantially 50% compared to the CW mode. By matching the 2D and 3D on-axis intensities, the total power consumption of the array 15 can be reduced to 8W.

  FIG. 22 is a graph of the optical window luminous intensity with respect to the viewing position of the window surface corresponding to the angle of the output light in the horizontal direction, and the left and right eyes in the example in which the display device is operated to provide the above-described autostereoscopic 3D display. FIG. 6 is a schematic diagram illustrating a method of adjusting the scaled luminous flux of the light illuminator element 15n for the illumination phase of FIG.

  In FIG. 22, the light distribution 272 for a gain greater than 1 is marked, and the positions of the left eye 560 and the right eye 562 are marked for the observer 99 at various viewing positions. For the observer 99 moving to the right of the optical axis, the position of the left eye is shown following the light distribution 272. For equal display brightness, the display must realize a luminosity difference between the left and right eyes of the observer that is Lambertian. Accordingly, the Lambertian light distribution 266 can be configured to provide the desired intensity 564 at the right eye position 562 across the position 262 of the window surface 106 through the left eye 560. Accordingly, the point 564 can be interpolated across the window surface for the right eye to provide the right eye light distribution 280. For an observer 99 moving to the left of the optical axis, the right eye can follow the light distribution 272, while the left eye can provide the light distribution 282 as well.

  FIG. 23A is a schematic diagram showing a graph of optical window luminous intensity versus viewing position on the window surface of waveguide 1 and a method of adjusting the scaled luminous flux of multiple light illuminator elements 15n for the right eye illumination phase. Therefore, after the correction indicated by the arrow, for the right eye 562, the waveguide light distribution 268 can be corrected so that the light distribution 272 is on the left side of the optical axis and the light distribution 280 is on the right side of the optical axis. Similarly, for the left eye 560, the waveguide light distribution 268 can be modified to place the light distribution 272 to the right of the optical axis and the light distribution 282 to the left of the optical axis. This controls the scaled luminous flux of the multiple light illuminator elements 15n as follows, according to the position detected by the observer, and the output light is modulated by either the left or right image. It can be realized by varying over the array 15 accordingly.

  FIG. 23B is a graph of luminous flux distribution for an array of light illuminator elements for the left and right eye illumination phases, and a method for adjusting the scaled light flux of a plurality of light illuminator elements 15n for waveguide 1 for the right eye illumination phase. FIG. Therefore, the right eye light flux distribution 279 may be different from the left eye light flux distribution 281. Arrow 271 indicates a decrease in the scaled luminous flux for each of the light sources corresponding to arrow 270 at each of the optical window positions 262 as compared to a constant luminous flux distribution 269, when the output light is modulated by the right image. When the right eye light flux distribution 279 is reached and the output light is modulated by the left image, the left eye light flux distribution 281 is reached.

  Advantageously, the power consumption of the array 15 can be substantially reduced in the 2D mode while maintaining equal brightness between the left and right eyes, thus improving display brightness. Similarly, an observer tracking display for an autostereoscopic display, a privacy display, or a high-efficiency 2D mode display can achieve low power consumption while maintaining the comfortable brightness characteristics of the display for left and right eye images. it can.

  In the above example, a light distribution 266 that is Lambertian or a light distribution 272 having a gain greater than 1 can be provided by controlling the scaled luminous flux. However, this is not limiting and the scaled luminous flux can be controlled to provide other shapes of light distribution. Here are some examples.

  FIG. 24 is a schematic diagram showing a graph of the optical window luminous intensity with respect to the viewing position on the window surface of the waveguide 1 corresponding to the angle in the output direction. It may be desirable to further modify the light distribution, for example, widen the area of Lambertian behavior near the location of the on-axis, but in the off-axis location compared to the light distribution 272. Increasing the slope of the light 274. Conveniently, the display can have substantially lambertian operation on-axis, and can have sufficient light for off-axis viewing while achieving low power consumption for off-axis viewing.

  FIG. 25 is a schematic diagram showing a further graph of the optical window luminous intensity with respect to the viewing position on the window surface of the waveguide 1 corresponding to the angle in the output direction. Thus, the light distribution 276 has a very narrow central area and can plummet to a background illumination profile.

  For example, the light distribution 266, 272, 274, or 276 can be controlled by user selection or automatic selection by a control system using, for example, the light flux controller 580 shown in FIG. Conveniently, the display characteristics can be modified to match battery level, privacy requirements, multiple viewers, display brightness environment, user experience, and other user requirements.

  FIG. 26A is a schematic diagram showing a further graph of the optical window luminous intensity versus viewing position on the window surface of the waveguide 1 corresponding to the angle of the output direction, and FIG. 26B is a light irradiator element that corrects the efficiency degradation of the light source. 2 is a schematic diagram showing a graph of luminous flux distribution with respect to the array. Light illuminator elements such as LEDs including gallium nitride blue emitters and yellow phosphors may undergo aging that can vary with use in scaled luminous flux and chromaticity. More specifically, a plurality of on-axis light irradiator elements can be used more frequently than a plurality of off-axis light irradiator elements that can result in non-uniform efficiency degradation in luminous flux divergence. Such errors can be corrected as shown by the scaled luminous flux distribution 279 from each of the light illuminator elements. Conveniently, the brightness distribution of the display can be maintained for the lifetime of the device.

  FIG. 27A is a schematic diagram showing a front view of a directional display device in landscape mode. Accordingly, display 290 can provide a plurality of vertical viewing windows 292. FIG. 27B is a schematic diagram showing a front view of the directional display device in the portrait mode. Therefore, when the display 290 is rotated, when such a display is used in the privacy mode or the green mode, the plurality of viewing windows 292 become horizontal, and the light distribution can be adjusted as shown in FIG. 27C. It may be desirable. FIG. 27C is a schematic diagram illustrating a further graph of optical window intensity versus viewing position on the window surface of waveguide 1 for the configuration of FIG. 27B. Therefore, the light distribution 294 is offset from the on-axis position to achieve high brightness for the preferred vertical viewing position, while maintaining low power consumption for other viewing angles while maintaining a visible display can do.

  FIG. 28 shows an observation of the direction perpendicular to the lateral direction at the same distance from the waveguide 1 (hereinafter referred to as “vertical”) and / or along the normal to the first guide surface of the waveguide 1. 1 is a schematic diagram showing a side view of a waveguide 1 and a viewing window 26 relating to a person's movement. FIG. 29 is a schematic diagram illustrating a graph of the luminous flux distribution for the array 15 of light illuminator elements and the method for adjusting the scaled light flux of the plurality of light illuminator elements 15n relative to the waveguide 1 according to the observer movement of FIG. It is. In this case, the scaled luminous flux is controlled according to the position of the observer detected by the sensor system, and varies according to the angle of the detected position of the observer in the lateral direction. The luminous intensity of the output light, which also varies depending on the position of the observer along the normal to the first guide surface of the waveguide 1, is provided. In the first embodiment, the luminous flux distributions 600, 602, and 604 can be provided for the vertical viewing positions 601, 603, and 605, respectively. Conveniently, the output light flux distribution can be adjusted accordingly when the observer leaves the preferred vertical viewing position. Here, the profiles of distributions 600, 602, 604 are shown as having different shapes, and the distribution shape can be modified to achieve, for example, a high quality Lambertian output for a preferred vertical viewing angle, Since gain performance for different viewing angles is higher, power is saved for viewing from these directions. Similarly, the viewer's movement towards the surface 607 away from the window surface 106 can be used to correct the light flux distribution across the array 15.

  In an observer tracking display, image flicker may be a problem for a moving observer. For an observer who is substantially at the window surface, the intensity can be changed simultaneously in the entire display due to the non-uniformity of the integrated optical window array 121 at the window surface. If the observer moves away from the window surface, or if the illumination system output is out of order, different areas of the display surface will appear to flicker by different amounts. It is desirable for the tracking and illumination steering system to cooperate to eliminate flicker for moving observers, which can be achieved by reducing the amplitude of the perceived intensity variation.

  For example, an eye moving towards an unilluminated optical window may see large intensity fluctuations on the display. It is desirable to increase the strength of this window prior to movement, which can reduce flicker artefact. However, when the strength of the plurality of optical windows, particularly the strength of the plurality of optical windows between the eyes located between the eyes of the observer, is increased, image crosstalk may be increased, and 3D image quality may be degraded. . Increasing the window strength further when the observer is substantially stationary, when low crosstalk is desired, and when the observer is moving, when low flicker is desired, results in additional flicker artifacts. obtain.

  FIG. 30 is a schematic diagram showing an arrangement of viewing windows while an observer moves between viewing positions in an example in which a display device is operated to provide the above-described autostereoscopic 3D display. Further, FIG. 30 shows another switching arrangement of the optical window array 721 arranged to reduce display flicker while substantially reducing image crosstalk while the viewer is moving. .

  In FIG. 30, a plurality of light irradiator elements 15n are controlled, and a left visual field window 730 including a plurality of optical windows respectively at positions corresponding to the left and right eyes of the observer according to the positions detected by the observer. And direct light into the right viewing window 732. In this example, there is a gap of one optical window between the left visual window 730 and the right visual window 732, or there may be no gap or the gap may be large. In this example, each of the left viewing window 730 and the right viewing window 732 includes five optical windows, but in general, the viewing window may include any number of optical windows.

  If the viewing window includes at least two optical windows, control the plurality of light illuminator elements 15n to output light having a scaled luminous flux that varies across each of the left viewing window 730 and the right viewing window 732. Can do. In the example of FIG. 30, the distribution of the light flux scaled over each of the left viewing window 730 and the right viewing window 732 is as follows.

  The distribution has a maximum value for the optical windows 730 and 734, which is the center of the left field window 730 and the right field window 732. In addition, the distribution for the left and right viewing windows 730 decreases on both sides of the maximum, ie, the optical windows 722 and 726 for the left viewing window 730 and the optical windows 724 and 728 for the right viewing window 732. The example of FIG. 30 shows a single optical window 722, 724, 726, 728 on each side of an optical window array 730 having a reduced and scaled beam, but generally one or more The optical window can have the same or different levels of reduced and scaled luminous flux. Reduced and scaled luminous flux of the optical windows 722, 724, 726, 728 can be achieved by changing the illumination level, pulse width, or pulse pattern, or any combination thereof.

  Advantageously, using the flux switching of FIG. 30 can improve display quality by substantially maintaining low crosstalk while reducing flicker perception by the viewer. Such an embodiment realizes a window suitable for both stationary and moving observers while reducing the effect of flickering by increasing the strength of adjacent or inter-optic optical windows. can do. More specifically, by reducing the scaled luminous flux on the side of the field window adjacent to the other field window, ie, the left field window 730 in the optical window 726 on the right field window 732 side, flicker is reduced. Similarly, for the right viewing window 732, the optical window 724 on the side of the left viewing window 730 is below the maximum value.

  Conveniently, for example, in battery-powered equipment, the number of illuminated optical windows can be reduced, thereby increasing the battery operating time. Reducing the number of illuminated optical windows may increase the flicker that is recognized.

  FIGS. 31-35 show several other distributions of scaled luminous flux that can be applied across the left and right viewing windows in the window plane, and a schematic graph of luminous intensity 700 for lateral (y-direction) input position 702. It is.

  FIG. 31 shows distributions 708 and 710 for the left eye 110 and the right eye 108 of the viewer i. The eye positions 704, 706 can then be used to determine intensity and crosstalk at a given location across the window surface. The arrangement of FIG. 31 is for a nearly perfect window, so that no crosstalk is observed, but such a window is usually not present.

  FIG. 32 shows distributions 712, 714 with sloping sides that cause the eye to see some light from adjacent viewing windows, causing unwanted image crosstalk and visual fatigue of the user.

  FIG. 33 is similar to FIG. 32, for example, where the light illuminator elements that implement the left viewing window 730 and the right viewing window 732 would be implemented by illumination having substantially the same scaled luminous flux. , Wider distributions 712, 714 are shown. Advantageously, crosstalk is reduced. However, small observer movements can reduce the display intensity that causes flicker for moving observers in the display on which the observer is tracked.

  FIG. 34 shows distributions 716, 718 similar to those that would be realized in the arrangement of FIG. Such an arrangement increases the intensity of the window near the observer's nose to the moving observer, but reduces image crosstalk to the stationary observer.

  FIG. 35 shows a distribution 714 for the right eye showing the display uniformity non-uniformity resulting from the non-uniform window intensity distribution. The viewer's right eye 108 can be positioned at a distance 746 between the window surface 106 and the display device 720. Thus, the light beam oriented from the display area 742 to the eye 108 is the light beam oriented to the uniform part 723 of the window 714, and the light beam from the display area 724 is directed to the non-uniform part 725 of the window 714. Light rays. Thus, the non-uniform window structure results in display non-uniformity for viewers who are not on the window surface, whereby regions 742 and 744 of display 720 have different intensity profiles. Therefore, it is desirable to reduce “hard” (steep) window boundaries and reduce the visibility of artifacts on the display surface. Therefore, the gradation arrangement of FIG. 30 can advantageously achieve uniform visibility performance improvement for moving observers and non-moving observers, while reducing image crosstalk. it can.

  FIGS. 36-41 are schematic diagrams showing some additional non-uniform light flux distributions that can be applied across the left and right viewing windows in the window plane, scaled for the input position 261 in the lateral (y-direction). 3 is a schematic graph of a light beam 263. In each case, the left eye viewing window 730 includes a plurality of optical windows 770 having a light flux distribution 772, and the right eye viewing window 732 includes a plurality of optical windows 771 having a light flux distribution 774. In each case, within each of the left viewing window 730 and the right viewing window 732, the luminous flux distributions 772, 774 are non-uniform with maximum values 773, 775, respectively, and these maximum values 773, 775 Decreases on both sides. In these examples, each of the left viewing window 730 and the right viewing window 732 includes five optical windows, but generally a similar distribution that decreases on either side of the maximum is arbitrary among at least three optical windows. Can be provided for a plurality of viewing windows, including

  The maximum values 773, 775 of the light illuminator elements are oriented by the optical system towards the viewer's pupil in the display being tracked by the optical system, according to the detected position of the viewer 99 obtained using the sensor system. Can be done. The maximum values 773, 775 can be arranged, for example, to be located 32 mm on each side of the measured nose position of the observer 99.

  The light flux distribution of FIG. 36 substantially achieves a similar profile of the optical window array and the field window array, but the diffusion and scattering within the optical system is such that the window array is compared to the distribution of FIG. It can be seen that it can act to blur.

  Compared with a viewing window having a substantially constant luminous flux distribution, the brightness of the observed image can be obtained, especially in the central region of the display area. The amount of light present in the system can be reduced, and thus crosstalk from stray light can be minimized. By providing a wider total window width for similar or lower crosstalk, the visibility of flicker artifacts to moving observers can be further reduced. In addition, the total power consumption of the device can be reduced to increase efficiency and reduce costs.

  FIG. 36 shows a situation in which the position detected by the observer 99 is aligned with the optical axis 232 of the waveguide 1, while FIG. 37 shows the observation moved laterally with respect to the optical axis 232 of the waveguide 1. The situation of the person 99 is shown. Therefore, the light flux distributions 772 and 774 of the left visual field window 730 and the right visual field window 732 can be displaced in the horizontal direction according to the position detected by the observer 99 while maintaining the intensity variation across the plurality of visual field windows. . Conveniently, the intensity variation of the plurality of outer optical windows can be reduced and the flickering of the moving observer 99 can be reduced compared to a plurality of uniform scaled beam illuminator elements for the viewing window. it can.

  FIG. 38 shows an alternative form of the left viewing window 730 and the right viewing window 732 for an observer moving laterally with respect to the optical axis 232 of the waveguide 1. In this case, the maximum values 773 and 775 can be configured to realize Lambertian light distribution of a plurality of optical windows in accordance with the light flux distributions 777 and 779. For example, the light distribution 769 can be tracked. Accordingly, light illuminator elements 770, 771 that are not at the maximum values 773, 775 can be corrected in the scaled luminous flux. Advantageously, the display may appear equally bright from a range of viewing angles while achieving crosstalk, flicker, and reduced power consumption. Alternatively, further power saving characteristics can be realized by further reducing the display brightness with respect to the off-axis viewing position. The light distribution 769 can be modified to increase the display gain and further reduce power consumption relative to the off-axis position.

  FIG. 39 shows, compared to FIG. 36, the left field of view for an observer who moved longitudinally along the optical axis 232 of the waveguide 1, ie, along the normal to the first guide surface of the waveguide 1. An alternative form of window 730 and right view window 732 is shown. In this case, the scaled light flux also fluctuates according to the detected longitudinal position, and in this example, each of the optical window and the field window including a flatter light flux distribution is provided. As shown in FIG. 35, variations in light intensity across multiple optical windows may provide variations in display uniformity. As the viewer moves longitudinally relative to the display, non-uniformity can increase as more optical windows can be captured across the display area. Therefore, it is desirable to reduce intensity variation across multiple optical windows.

  In addition, the user can select the preferred gain characteristics for the entire display to fit personal preferences for efficiency, crosstalk, uniformity and image flicker, and measured eye spacing within the window.

  40 and 41 show alternative forms of the left viewing window 730 and the right viewing window 732. Here, the scaled luminous flux of the plurality of light illuminator elements oriented in the plurality of optical windows between the observer's eyes and located between the maximum value 773 and the maximum value 775 is the maximum value 773, A reduction of the scaled luminous flux of the plurality of light illuminator elements located outside 775. Such an arrangement provides some light towards the edge of the display for the viewer 99 away from the window surface 106 while achieving a relatively uniform brightness for the central area of the display. Advantageously, display uniformity is maintained while reducing perceived image flicker.

  In the above example, the display device is operated to provide an autostereoscopic 3D display. However, the display device is operated to display a 2D image, and a plurality of light sources 15 are operated by the control system, so that the observer 99 In the case of directing light to a single field window according to the detected position, a similar variation of the light beam scaled across the field window can be applied. An example of this is described below.

  FIG. 42 is a schematic diagram showing a horizontally oriented 2D directional display. Display device 100 is configured to provide a single viewing window 790 according to the detected position of lateral observer 99. The plurality of light sources are controlled to output light having a scaled luminous flux that varies across the array of light sources and have a maximum value 773, 775 substantially aligned with the right eye 791 and left eye 792 of the viewer 99. It provides a light intensity that varies with the angle of the detected position of the observer in the light 793. The array 15 is arranged by a plurality of non-irradiated light irradiator elements 797 and an irradiated group 804 of a plurality of light irradiator elements of the array 15 that achieves maximum values 773 and 775 in the viewing window 790. When array 15 is arranged with a substantially constant pitch 803 and imaged in combination with asymmetric diffusers 68 and other scattering components in the display, non-uniformities in the viewing window can be minimized. .

  Accordingly, the array 15 of light illuminator elements can be arranged at a constant pitch 803 at different input positions 261 in the transverse direction across the input end of the waveguide, so that the scaled light flux is irradiated with a plurality of light irradiations. This is the actual luminous flux of the vessel element 15n.

  Further, a plurality of light illuminator elements 802 corresponding to an off-axis viewing position having a larger pitch and / or a lower scaled luminous flux compared to a plurality of light illuminator elements at an on-axis viewing position. Can be provided. In combination with controlling the scaled luminous flux of multiple light emitter elements for more on-axis positions, such multiple light emitter elements are capable of combining light without compromising the desired optical window output. The cost of the array of irradiator elements can be reduced.

  FIG. 43 is a schematic diagram showing a graph of scaled luminous flux versus input position for the display of FIG. Accordingly, the illumination of the 2D display can be configured to reduce power consumption compared to a Lambertian illuminated display. The operation of the display is similar to that shown in FIGS. 36-41, but the group 804 is arranged to be illuminated in a single phase for both eyes and may provide continuous operation. Conveniently, it can reduce the power consumption of the device, while achieving substantially the same brightness in the center of the display for the viewer on the window and minimizing the display flicker for the moving observer Can be. Furthermore, the spatial light modulator 48 can operate continuously rather than in synchronization with the illumination phases of the left and right eyes, reducing the cost of the spatial light modulator 48.

  FIG. 44 is a schematic diagram showing a vertically oriented 2D directional display. When the eyes are arranged in parallel in a range in the x-axis of the plurality of viewing windows 795, the height 808 of the vertically oriented (lateral) window 795 is set to the width of the horizontally oriented (lateral) window. The light distribution 796 can be provided lower than 806. Therefore, compared with the configuration of FIG. 42, the power consumption can be advantageously further reduced.

  FIG. 45 is a schematic diagram illustrating a graph of scaled luminous flux versus input position for the display of FIG. Therefore, the light flux distribution 800 of the plurality of optical windows 812 may be narrower than the configuration of FIG. 44 to form a viewing window 794 and may advantageously provide a single maximum value 810, The center of the display is optimally illuminated for the on-axis viewing position away from the window. The field window 794 may be stationary or may be adjusted according to the position detected by the observer 99.

  Accordingly, the light irradiator element is selectively operated to perform the step of directing light on the plurality of fluctuating optical windows corresponding to the output direction, and includes at least two simultaneously irradiated optical windows 812. The light can be directed to at least one field window 794, and the plurality of light illuminator elements vary according to the detected position of the observer 99 and further across the plurality of optical windows 812 of the at least one field window 794. Control is performed to output light having a varying light flux linear density 263.

  FIG. 46 is a schematic diagram showing a control system and a front view of the directional backlight device including the directional backlight described above, including the waveguide 1 and the array 15 of light irradiator elements. The directional backlight device includes the above-described control system that implements a method for controlling a plurality of light irradiator elements 15n that calibrate drive signals as follows.

  The light beam 210 from the light illuminator element 216 is directed to the reflective end 4, reflected, and directed back to the input end 2. A part of the light from the light source 216 will be extracted by the plurality of light extraction mechanisms 12, while a part of the light will be incident on at least a part of the input end 2. Sensor elements 208, 214 can be arranged at the input ends of regions 209, 215 on either side of array 15 and outside the lateral extent of array 15. In region 212, the presence of an illumination void causes light from light source 216 to substantially not enter sensor 214, but light from light source 216 will enter sensor 208. Each of the sensors 208, 214 can include a photometric sensor. As shown in FIG. 46, the sensors 208, 214 may preferably include optical filters 202, 206 and photometric sensors 200, 204. With such a configuration, both light intensity measurement and color coordinate measurement can be conveniently provided for the light from the light source 216. Similarly, the light beam 220 from the light source 218 cannot enter the sensor 208 but enters the sensor 214. For on-axis measurement, both sensors 208 and 214 detect light from each of the on-axis light emitter elements 217.

  Using the light emitter element driver 233, which can be a current driver that provides grayscale control to the drive line 244 and provides a drive signal to the array of light emitter elements, the signals measured from the sensors 208, 214 are It can be passed to an illumination controller 74 that drives 15 light illuminator elements. The illumination controller 74 calibrates the drive signal supplied to the plurality of light illuminator elements 15n in response to the measured signal representing the sensed light as follows.

  The array light flux distribution controller 224 can include a stored reference tone profile 230 from before the screen measurement that can be provided during manufacturing, including, for example, the light flux distribution data for the distribution 550 of FIG. 21B. . This allows the control system to output a scaled beam having a predetermined distribution across the array of light sources, for example, to vary the scaled beam as described above.

  For example, data from sensors 208, 214 can be provided to a calibration measurement system 222 that can provide data to a look-up table 226 within the luminous flux distribution controller 224. Further selection of light distribution (eg, selecting from light distributions 266, 272, 274, 276, 294) may be provided by the selection controller 228. The selection controller can have user input or automatic input determined by sensing display viewing conditions. For example, the number of viewers, room brightness, display orientation, image quality settings, and / or power saving mode settings can be used to vary the selected distribution.

  In the manufacture of the device, the output of the sensors 208, 214 corresponding to each of the light sources of the array 15 can be compared with signals from a camera or detector placed on the display window. This provides an initial calibration or reference of the internal sensor for light at the window surface. Such a calibration can be stored in a look-up table or the like.

  In operation in the calibration mode, a single light emitter element of the array 15 is illuminated and the sensors 208, 214 can measure signals for the light emitter element. The light illuminator element is extinguished and the next light source in the array is operated and measurements are taken. The output of a series of measurements can be compared to factory calibration, which can interpolate the output intensity for a given luminous flux distribution. Next, the controller 224 and the light irradiator element controller 233, which are appropriately configured to realize a desired light flux distribution, derive an appropriate light flux distribution for the required light distribution.

  Conveniently, the combination of sensors 208, 214 can measure light from the entire array 15 and achieve the desired light distribution.

  Thus, a plurality of sensor elements 208 arranged in the region 209 of the input end 2 outside the array 15 of lateral light illuminator elements can be used in the sensing of light incident on the input end 2. In the sensing of light incident on the input end 2, sensor elements 208 arranged in the regions 209, 215 of the input end 2 outside the array 15 of light emitter elements in the lateral direction on both sides of the array of light emitter elements, 214 can be used.

  The sensor system can be configured with the waveguide 1 only during display fabrication for characterization purposes and is removed after product fabrication is complete. It is desirable to configure the sensor system with the waveguide 1 during normal operation. During display power-up, an in-field calibration phase can be applied. The spatial light modulator may be configured with a black image during calibration and can be invisible to the user of the calibration phase. The calibration phase can be performed, for example, on a daily, weekly, or monthly basis to correct for artifacts over time as shown in FIGS. 26A-26B.

  FIG. 47 is a schematic diagram showing a control system and a front view of the directional backlight device, similar to FIG. 47, but as described below, by using the light emitter elements of the array 15 in the sensing mode, With the following modification of removing and replacing 214. Thus, in the calibration mode of operation, the light illuminator elements are illuminated and all of the other light illuminator elements are configured to sense light rather than emit light. The light sensed at the input end is used as described with reference to FIG.

  When sensing light using a plurality of light illuminator elements 15n, integral intensity measurements are taken and the total detected intensity is averaged. Thus, although multiple light illuminator elements cannot provide high quality measurements individually, the array signal-to-noise ratio can improve performance. Once performance is calibrated and compared to factory settings, the required light distribution can be achieved as described with reference to FIG. Advantageously, the cost of the sensor can be reduced or eliminated, sensing over a wide range of locations at the input end, and optical performance can be averaged.

  FIG. 48 is a schematic diagram illustrating an apparatus for driving a light emitter element for a calibration mode of operation. In this case, the light irradiator element is a plurality of LEDs 248, and light is sensed by operating the plurality of LEDs 248 with a reverse bias. FIG. 48 shows a semiconductor pn junction device that includes an LED 248 that can be operated as a first forward-biased light emitter element and can also be operated in reverse bias as a photodetector. During operation with forward bias, the LED 248 is driven from a drive amplifier 244 that has a signal input 243 and an enable input 251 so that when the switch 253 is in the GND position 254, the amplifier 244 Is enabled and LED 248 emits light 252 in response to signal input 243.

  When switch 253 is in position 256, a positive voltage is applied to the cathode of LED 248, thereby arranging it in reverse bias. With reverse bias, LED 248 operates to detect light 250 in cooperation with optical amplifier 246. Thus, the circuit 240 allows the pn junction device 248 to be operated as an LED or photodetector.

  Advantageously, this enables the same LED array 15 to function as a photodetector array with suitable circuitry 240. Each of the light sources in the array can have the arrangement of FIG. 48, and each individual pn junction device in array 15 can have its own optical amplifier 246.

  FIG. 49 is a schematic diagram showing a light illuminator element array in a calibration mode of operation. Also, as shown in FIG. 49, when the LED by the drive amplifier 244 can be separated from the pn junction driven as a detector by the switch 249, the pn junction of the array 15 is driven with a forward bias. obtain. Similar switches may be configured at other positions in the array 15. Conveniently, the current outputs of multiple pn junction devices 248 can be summed at the virtual ground input of the optical amplifier 246. Advantageously, the sensitivity of detection can be improved and the number of optical amplifiers 246 can be reduced.

  The light illuminator element is usually a plurality of white LEDs, more specifically a gallium nitride blue light emitting chip, and a wavelength converter that is usually a phosphor configured to convert part of the blue light into yellow light. A plurality of LEDs, including layers. Combining blue light and yellow light can achieve white light output. In operation, the blue and yellow light emitting elements can change their output at different rates, and thus the color temperature of the white light output can change over time. Color variations may cause chromaticity variations of multiple optical windows, and thus recognized luminance and chromaticity changes in the viewing window. Such changes may increase the display flicker for a moving observer and may achieve non-uniformity across the display area. It is desirable to correct the output of a plurality of light irradiator elements for such chromaticity changes.

  FIG. 50 is a schematic diagram illustrating a front view of a light illuminator element array arranged to achieve color correction. The light irradiator element array 400 can be aligned with the input end 402 of the waveguide 1. Each of the array of light emitter element packages 412 may include a first gallium nitride chip 404 and a second gallium nitride chip 408, and phosphors 406, 410 respectively aligned, the pair being an input The openings 402 are aligned in a vertically long arrangement. The individual drive lines 405, 407 are arranged to provide the desired luminous flux distribution across the array 15 of light emitter elements. The phosphor may be a rare earth macroscopic phosphor or a quantum dot phosphor.

  FIG. 51 is a schematic diagram showing a front view of a further array of light illuminator elements arranged to achieve color correction. The package can be arranged in a landscape orientation with respect to the input end 402, and thus the height of the input end may be lower, and higher efficiency can be achieved. In such an arrangement, adjacent optical windows in the window surface 106 can have different chromaticity appearances, but the diffusion of the lateral optical windows by the asymmetric diffuser 68 causes chromaticity variations in the window surface. Can be configured to reduce. Advantageously, this arrangement can achieve higher efficiency of the waveguide 1 and reduced crosstalk for a given height of the reflective end 4 compared to the arrangement of FIG.

  FIG. 52 is a schematic diagram showing a graph of chromaticity variation of an optical window and a method of correcting the chromaticity variation. Thus, in the CIE 1931 xy chromaticity diagram with spectral trajectory 420 and white point trajectory 426, the factory setting of chromaticity coordinates (which is the average of two light sources 404, 406 and two light sources 408, 410) is It can be provided as point 422. After aging, the average chromaticity can move in the direction 430 to the point 424. As shown in FIG. 46, such chromaticity can be measured by sensor and filter elements 204, 206 and 200, 202, respectively. The control system of FIG. 46 further provides different corrected drive signals along drive lines 405, 407 for each of the light illuminator elements to correct for the variation in output chromaticity and return to point 422. The chromaticity coordinates can be moved to 428.

  Further, the chromaticity and the output of the multiple light illuminator elements can vary with temperature. Thus, a plurality of light illuminator elements in portions of the array 15 that are frequently used, such as for on-axis positions, can operate at a higher temperature than portions of the array that are less frequently used. Thus, in operation, the brightness of the plurality of light illuminator elements can vary over time due to temperature effects. Sensors 208, 214 may be configured to operate during display operation to correct for temperature variations with the control system described above. Thus, a non-operating light illuminator element or a separate sensor can be configured to continuously monitor the output brightness and dynamically provide adjustment of the light illuminator element output.

  FIG. 53 is a schematic diagram illustrating a front view of an array of light illuminator elements, and FIG. 54 is a schematic diagram illustrating a front view of the array of light illuminator elements and a method of correcting a failure of the light illuminator elements. In operation, the viewing window 26 may include light from an adjacent optical window 249 so that, for a given viewing position on the window surface, the viewing window is, for example, in at least two, preferably region 560. As shown, includes light from more than two light irradiator elements. Failure of the light illuminator element can result in a degradation of the viewing window profile and can be detected by a sensing system as shown in FIG. Such a failure can be corrected as described above by further increasing the drive to drive lines 566, 568 to multiple nearby light illuminator elements and eliminating the drive to drive line 564.

  The pitch 421 of the light sources 420 of the array 15 of light irradiator elements 15n has a width 422 of light mainly including yellow light for phosphor emission, as compared with a width 424 including a GaN chip area including much blue light. 426 may be included. Further, the gap 428 (which may include a portion of the mechanical, thermal and electrical package of the light source) may not have light emission. Thus, the scaled luminous flux is a measure of the average luminous flux over the pitch 421. The pitch 421 can vary across the lateral width of the array 15 of light illuminator elements 15n.

  As used herein, the terms “substantially” and “approximately” give industry-acceptable tolerances on the corresponding terms and / or the relativeities between items. Is. Such acceptable ranges accepted in the industry are in the range of 0 percent to 10 percent, including but not limited to component values, angles, and the like. Such relativity between items ranges from about 0 percent to 10 percent.

  Although various embodiments in accordance with the principles disclosed herein have been described above, these embodiments have been presented for illustrative purposes only and are not intended to be limiting. Please note that. Accordingly, the breadth and scope of this disclosure should not be limited by any of the above-described exemplary embodiments, but is defined only in accordance with any of the claims and their equivalents derived from this disclosure. Should be. Furthermore, while the advantages and features described above are provided in the described embodiments, the applications of such published claims may be used to implement methods and structures that realize some or all of the advantages described above. It is not limited to.

  In addition, section headings herein are provided as organizational cue otherwise as set forth in 37 CFR §1.77. These headings shall not limit or characterize the embodiments defined in the claims that may arise from this disclosure. Specifically, there is a heading of “technical field”, which is merely an example, but the scope of the claims is limited by the expression selected under this heading in order to explain the so-called field. Never happen. Furthermore, a description of a technology in “Background” should not be construed as an admission that the specific technology is prior art to any embodiment (s) in this disclosure. Neither should the “Summary of the Invention” be considered as a characterization of the embodiment (s) set forth in the appended claims. Further, in this disclosure, any reference to “invention” in the singular should not be used to claim that there is only one novel point in the present disclosure. Embodiments may be set forth according to the present disclosure in accordance with the limitations of the multiple claims that are issued. Accordingly, these claims protect these by defining this embodiment (s) and their equivalents. In all instances, the scope of these claims should be considered a unique advantage in light of the present disclosure and should not be limited by the headings set forth herein.

Claims (77)

A method for controlling an array of light sources of a directional backlight, comprising: a waveguide having an input end; and an array of light sources disposed at different input positions in a lateral direction across the input end of the waveguide. And
The waveguide further includes opposing first and second guide surfaces for directing light along the waveguide, the first guide surface being determined by the input location. In the output direction distributed in a direction transverse to the normal line, the input light from the plurality of light sources is output as the output light and is oriented in the plurality of optical windows through the first guide surface. And
The method includes selectively manipulating the plurality of light sources to direct light into a plurality of optical windows that vary in light, the plurality of light sources being associated with each of the plurality of light sources in the lateral direction. A method controlled to output light having a luminous flux that is inversely scaled by a given width and varies across the array of light sources.   Light having the scaled luminous flux varying across the array of light sources in a luminous flux distribution having the input position across the input end, wherein the plurality of light sources have a maximum value and decrease on both sides of the maximum value. The method of claim 1, wherein the method is controlled to output.   The method of claim 2, wherein the maximum value of the luminous flux distribution is for the plurality of light sources aligned with an optical axis of the waveguide.   The scaled luminous flux that varies with the plurality of light sources in the luminous flux distribution having the input position that generates the luminous intensity of the output light that varies with the angle of the output direction in a light distribution that is Lambertian. The method according to any one of claims 1 to 3, wherein the method is controlled to output light having:   The plurality of light sources are Lambertian and have a maximum luminous intensity corresponding to the maximum value of the luminous flux distribution that is greater than a conceptual light distribution in which the total luminous intensity across all output directions is the same as the actual light distribution. In actual light distribution, in the light flux distribution having the input position that generates the luminous intensity of the output light that varies depending on the angle of the output direction, the light having the scaled light flux that is varied by the light source is output. The method according to any one of claims 1 to 3.   A display device wherein the directional backlight further includes a transmissive spatial light modulator configured to receive the output light from the first guide surface and modulate the output light to display an image The method further includes detecting an observer position across the display device, and selectively manipulating the plurality of light sources to direct light into a plurality of optical windows. Is implemented to direct light into a plurality of optical windows according to the detected position of the observer, the plurality of light sources varying across the array of light sources according to the detected position of the observer The method of claim 1, wherein the method is controlled to output light having the scaled luminous flux.   In the light distribution having a Lambertian property, the plurality of light sources generate the intensity of the output light that varies according to the angle of the detected position of the observer in the lateral direction. The method of claim 6, wherein the method is controlled to output light having the scaled light flux that varies across the plurality of light sources according to detected positions.   In the actual light distribution, wherein the plurality of light sources are Lambertian and have a maximum luminous intensity greater than a conceptual light distribution in which the total luminous intensity across all output directions is the same as the actual light distribution, The scaled luminous flux that varies across the plurality of light sources according to the detected position of the observer in a manner that generates a luminous intensity of the output light that varies with the angle of the detected position of the observer. The method of claim 6, wherein the method is controlled to output light having:   The plurality of light sources depends on the detected position of the observer in the lateral direction, the angle of the detected position of the observer, and a direction along a normal to the first guide surface. 7. Controlled to output light having the scaled luminous flux that varies across the plurality of light sources in accordance with the detected position of the observer in a manner that produces a varying intensity of the output light. 6. The method according to 6.   In at least one viewing window, wherein the step of selectively manipulating the plurality of light sources to direct light into a plurality of fluctuating optical windows corresponding to the output direction includes at least two simultaneously illuminated optical windows. Wherein the plurality of light sources varies according to the detected position of the observer and further varies across the plurality of optical windows of the at least one field window. 10. The method according to any one of claims 6 to 9, wherein the method is controlled to output light having:   The at least one field window includes at least three simultaneously illuminated optical windows, and the plurality of light sources have a maximum value and decrease on both sides of the maximum value, the at least three simultaneously in a field window distribution. The method of claim 10, wherein the method is controlled to output light having the scaled luminous flux that varies across the illuminated optical window.   Further comprising controlling the spatial light modulator to display a temporally multiplexed left and right image, wherein the selective operation of the plurality of light sources is performed according to the detected position of the observer, 9. The method according to any one of claims 6 to 8, wherein the method is performed synchronously to orient the displayed left and right images within a plurality of optical windows corresponding to the left and right eyes of the observer.   13. The light source of claim 12, wherein the plurality of light sources are controlled to output light having a flux line density that varies across the array of light sources, depending on whether the output light is modulated by a left or right image. The method described.   The plurality of light sources generate luminosity of the output light that varies according to the angle of the left and right eyes of the observer in the lateral direction, the luminosity being Lambertian, and the output light is left 14. The method of claim 13, wherein the method is controlled to output light having the scaled luminous flux that varies across the array of light sources, depending on whether it is modulated by the right image or the right image.   In the left viewing window, the step of selectively manipulating the plurality of light sources to direct light into a plurality of fluctuating optical windows corresponding to the output direction includes at least two simultaneously illuminated left optical windows. And in a right viewing window including at least two simultaneously illuminated right optical windows, wherein the plurality of light sources further extends over the at least two optical windows of each of the left and right viewing windows. 15. A method according to claim 13 or 14, wherein the method is controlled to output light having the scaled luminous flux varying.   The plurality of light sources has a maximum value and varies across the at least two simultaneously illuminated left optical windows in a left field window distribution that decreases on a side of the maximum value adjacent to the right field window; and a maximum Output light having the scaled luminous flux that varies across the at least two simultaneously illuminated right optical windows in a field window distribution having a value and decreasing on the maximum value side adjacent to the left field window The method of claim 15, wherein the method is controlled to.   The method of claim 16, wherein the left viewing window distribution decreases on both sides of the maximum value and the right viewing window distribution decreases on both sides of the maximum value. A display device wherein the directional backlight further includes a transmissive spatial light modulator configured to receive the output light from the first guide surface and modulate the output light to display an image Is part of
The method further includes controlling the spatial light modulator to display a temporally multiplexed left and right image, wherein the selective operation of the plurality of light sources is at least two simultaneously illuminated left Implemented in synchronization with directing light in a left viewing window including an optical window and in a right viewing window including at least two simultaneously illuminated right optical windows, wherein the plurality of light sources are the left and right viewing windows. The method of claim 1, wherein the method is controlled to output light having the scaled luminous flux further varying over each of the at least two optical windows.   The first guide surface is configured to guide light by total internal reflection and in a direction that allows the second guide surface to exit through the first guide surface as the output light. A plurality of light extraction mechanisms directed to reflect light guided through the waveguide, and the plurality of light extraction mechanisms configured to direct light through the waveguide without extracting light. 19. A method according to any one of the preceding claims, comprising a plurality of intermediate regions between light extraction mechanisms.   The method of claim 19, wherein the second guide surface has a stepped shape including a plurality of facets that are the plurality of light extraction features and a plurality of intermediate regions.   The plurality of facets of the second guide surface are configured to reflect light by total internal reflection, whereby the luminous flux of the output light reflected by the plurality of facets is The ratio of the light flux has fluctuations for different light sources, and the light sources vary across the array of light sources in a manner that corrects the fluctuations in the light flux of the output light reflected by the facets. 21. The method of claim 20, wherein the method is controlled to output light having the scaled luminous flux. The first guide surface is configured to direct light by total internal reflection, and the second guide surface is substantially planar for outputting light through the first guide surface; Tilt to an angle that reflects light in a direction that changes the total internal reflection,
19. The display device according to any one of the preceding claims, wherein the display device further comprises a deflection element extending over the first guide surface of the waveguide for deflecting light towards a normal to the spatial light modulator. The method according to item.   The waveguide further includes a reflective end facing the input end for reflecting light from the input light back through the waveguide, the waveguide being input light from the plurality of light sources. 23. The method of any one of claims 1-22, wherein the method is configured to direct light as output light through the first guide surface after reflection from the reflective end.   24. The method of claim 23, wherein the reflective end has a lateral positive power across the waveguide.   The array of light sources is arranged at different input positions at a constant pitch in the lateral direction across the input end of the waveguide so that the scaled light flux is the actual light flux of the plurality of light sources. 25. A method according to any one of claims 1 to 24. A directional display device,
A display device,
A waveguide having an input end;
Disposed at different input positions laterally across the input end of the waveguide, the waveguides having opposing first and second guide surfaces for directing light along the waveguide. In addition, the waveguide includes, as output light, input light from a plurality of light sources in an output direction distributed in a direction transverse to a normal to the first guide surface determined by the input position. An array of light sources configured to be oriented in the plurality of optical windows through the guide surface;
A transmissive spatial light modulator configured to receive the output light from the first guide surface and modulate the output light to display an image; and a display device;
Selectively manipulating the plurality of light sources to direct light within the fluctuating optical windows and controlling the plurality of light sources to reverse by a width associated with each of the lateral light sources And a control system configured to output light having a luminous flux that is scaled and varies across the array of light sources.   The control system controls the plurality of light sources to vary across the array of light sources in a luminous flux distribution having the input position across the input end having a maximum value and decreasing on both sides of the maximum value. 27. A directional display device according to claim 26, configured to output light having the scaled luminous flux.   28. The directional display device according to claim 27, wherein the maximum value of the luminous flux distribution relates to the plurality of light sources aligned with the optical axis of the waveguide.   In the luminous flux distribution having the input position, wherein the control system controls the plurality of light sources to generate a luminous intensity of the output light that varies depending on an angle of the output direction in a light distribution having a Lambertian property. 29. A directional display device according to any one of claims 26 to 28, configured to output light having the scaled luminous flux that fluctuates according to.   The control system controls the plurality of light sources to be lambertian and has a maximum luminous flux distribution greater than a conceptual light distribution in which the total luminous intensity over all output directions is the same as the actual light distribution In the actual light distribution having a maximum luminous intensity corresponding to the scaled light flux distribution having the input position for generating the luminous intensity of the output light that varies with the angle of the output direction, the scaled variable with the plurality of light sources. 29. A directional display device according to any one of claims 26 to 28, configured to output light having a luminous flux.   The control system further includes a sensor system configured to detect a position of the observer across the display device, the control system selectively operating the light source to detect the detected of the observer Configured to direct light into a plurality of optical windows according to position, wherein the control system controls the plurality of light sources to vary across the array of light sources according to the detected position of the observer 27. A directional display device according to claim 26, configured to output light having the scaled luminous flux.   The control system controls the plurality of light sources to generate a luminous intensity of the output light that varies according to an angle of the detected position of the observer in the lateral direction in a light distribution that is Lambertian. 32. The directional display device of claim 31, configured to output light having the scaled luminous flux that varies across the plurality of light sources according to the detected position of the observer.   The control system controls the plurality of light sources to have a maximum luminous intensity greater than a conceptual light distribution that is Lambertian and the total luminous intensity across all output directions is the same as the actual light distribution. In the light distribution, the plurality of light sources according to the detected position of the observer in a form that generates a luminous intensity of the output light that varies according to an angle of the detected position of the observer in the lateral direction. 32. The directional display device according to claim 31, configured to output light having the scaled luminous flux varying over time.   The plurality of light sources depends on the detected position of the observer in the lateral direction, the angle of the detected position of the observer, and a direction along a normal to the first guide surface. 7. Controlled to output light having the scaled luminous flux that varies across the plurality of light sources in accordance with the detected position of the observer in a manner that produces a varying intensity of the output light. 32. The directional display device according to 31.   The control system controls the plurality of light sources to direct light into at least one field window including at least two simultaneously illuminated optical windows, varying according to the detected position of the observer; 35. The directivity according to any one of claims 31 to 34, configured to output light having the scaled luminous flux that further varies across the plurality of optical windows of the at least one viewing window. Display device.   The at least one field window includes at least three simultaneously illuminated optical windows, and the control system controls the plurality of light sources to have a maximum value and to decrease on both sides of the maximum value; 36. The directional display device of claim 35, configured to output light having the scaled luminous flux that varies across the at least three simultaneously illuminated optical windows in a field window distribution.   An autostereoscopic display device, wherein the control system controls the spatial light modulator to display temporarily multiplexed left and right images, and according to the detected position of the observer, the observation 32. The plurality of light sources are configured to be selectively operated in synchronization with the orientation of the displayed left and right images in a plurality of optical windows corresponding to the left and right eyes of the person. 34. The directional display device according to any one of -33.   The control system controls the plurality of light sources to output light having the scaled luminous flux that varies across the array of light sources according to whether the output light is modulated by a left or right image. 38. A directional display device according to claim 37, configured to:   The control system controls the light source to generate a luminous intensity of the output light that varies with the angle of the left and right eyes of the observer in the lateral direction, where the luminous intensity is Lambertian. 39. A directivity according to claim 38, configured to output light having the scaled luminous flux varying across the array of light sources, depending on whether the output light is modulated by a left or right image. Display device.   The control system controls the plurality of light sources in a left viewing window including at least two simultaneously illuminated left optical windows and in a right viewing window including at least two simultaneously illuminated right optical windows; Configured to direct light, and wherein the control system controls the plurality of light sources to direct the light having the scaled luminous flux further varying across the at least two optical windows of each of the left and right viewing windows. 40. A directional display device according to claim 38 or 39 configured to output.   The control system controls the plurality of light sources to illuminate the at least two simultaneously in a left viewing window distribution having a maximum value and decreasing on a side of the maximum value adjacent to the right viewing window. Fluctuating across the at least two simultaneously illuminated right optical windows in a field window distribution that varies across the left optical window and has a maximum value and decreases on the side of the maximum value adjacent to the left field window; 41. A directional display device according to claim 40, configured to output light having the scaled luminous flux.   42. The directional display device according to claim 41, wherein the left viewing window distribution decreases on both sides of the maximum value and the right viewing window distribution decreases on both sides of the maximum value. An autostereoscopic display device,
The control system is configured to control the spatial light modulator to display temporally multiplexed left and right images, the control system including at least two simultaneously illuminated left optical windows Configured to control the plurality of light sources in synchronization with directing light within a left viewing window and within a right viewing window including at least two simultaneously illuminated right optical windows, the control system comprising: 27. configured to control the plurality of light sources to output light having the scaled luminous flux further varying across the at least two optical windows of each of the left and right viewing windows. Directional display device.   The first guide surface is configured to guide light by total internal reflection and in a direction that allows the second guide surface to exit through the first guide surface as the output light. A plurality of light extraction mechanisms oriented to reflect light directed through the waveguide, and the plurality of light extraction mechanisms configured to direct the light through the waveguide without extracting light. 44. A directional display device according to any one of claims 26 to 43, comprising a plurality of intermediate regions between light extraction mechanisms.   45. The directional display device according to claim 44, wherein the second guide surface has a stepped shape including a plurality of facets as the plurality of light extraction mechanisms and the plurality of intermediate regions.   The plurality of facets of the second guide surface are configured to reflect light by total internal reflection, whereby the light flux of the output light reflected by the plurality of facets is The ratio of the luminous flux varies with respect to a plurality of different light sources, and the control system controls the plurality of light sources to correct the variation in the luminous flux of the output light reflected by the plurality of facets. 46. The directional display device of claim 45, configured to output light having the scaled luminous flux that varies across the array of light sources.   The first guide surface is configured to direct light by total internal reflection, and the second guide surface is substantially planar for outputting light through the first guide surface; The first guide surface of the waveguide tilted at an angle to reflect light in a direction that changes the total internal reflection and the display device deflects the light toward a normal to the spatial light modulator 44. The directional display device according to any one of claims 26 to 43, further comprising a deflection element extending over the directional display.   The waveguide further includes a reflective end facing the input end for reflecting light from the input light back through the waveguide, the waveguide being input light from the plurality of light sources. 48. A directional display device according to any one of claims 26 to 47, wherein the directional display device is configured to be oriented as output light passing through the first guide surface after reflection from the reflection end.   49. A directional display device according to claim 48, wherein the reflective end has a lateral positive refractive power across the waveguide.   The array of light sources is disposed at different input positions at a constant pitch in the lateral direction across the input end of the waveguide, so that the scaled light flux is the actual light flux of the plurality of light sources. The directional display device according to any one of claims 26 to 49. A method for controlling an array of light sources of a directional backlight, comprising: a waveguide having an input end; and an array of light sources disposed at different input positions in a lateral direction across the input end of the waveguide. And
The waveguide reflects the input light from the plurality of light sources through the waveguide by reflecting opposite first and second guide surfaces for guiding light along the waveguide. A reflective end opposite the input end for returning, wherein the waveguide is in an output direction distributed laterally to a normal to the first guide surface determined by the input position, After reflection from the reflection end, the input light from the plurality of light sources is output light, and is configured to be oriented in the plurality of optical windows through the first guide surface,
The method
Selectively operating the plurality of light sources to provide the light source with a drive signal that directs light within a fluctuating optical window corresponding to the output direction;
Sensing light incident on the input from the light source after reflection from the reflective end, and calibrating the drive signal in response to the sensed light incident on the input. Method.   52. The method of claim 51, wherein in sensing the light incident on the input end, sensor elements arranged in the area of the input end outside the array of light sources in the lateral direction are used.   53. In the sensing of light incident on the input end, sensor elements arranged in the region of the input end outside the array of light sources in the lateral direction on both sides of the array of light sources are used. The method described.   52. The method of claim 51, wherein the sensing of light incident on the input uses a light source of the array that is not operated simultaneously.   55. The method of claim 54, wherein the plurality of light sources are a plurality of light emitting diodes, and the sensing of the light incident on the input uses the array's light sources operated in reverse bias.   56. The level of the drive signal is calibrated such that the plurality of light sources output light having a light flux having a predetermined distribution across the array of light sources. Method.   The first guide surface is configured to guide light by total internal reflection and in a direction that allows the second guide surface to exit through the first guide surface as the output light. A plurality of light extraction mechanisms directed to reflect light directed through the waveguide, and the plurality of lights configured to direct light through the waveguide without extracting light 57. A method according to any one of claims 51 to 56, comprising a plurality of intermediate regions between extraction mechanisms.   58. The method of claim 57, wherein the second guide surface has a stepped shape including a plurality of facets that are the plurality of light extraction features and the plurality of intermediate regions.   The first guide surface is configured to direct light by total internal reflection, and the second guide surface is substantially planar for outputting light through the first guide surface; The first guide surface of the waveguide tilted at an angle to reflect light in a direction that changes the total internal reflection and the display device deflects the light toward a normal to the spatial light modulator 59. A method as claimed in any one of claims 51 to 58, further comprising a deflection element extending across.   60. A method according to any one of claims 51 to 59, wherein the reflective end has a lateral positive refractive power across the waveguide.   The display device further includes a transmissive spatial light modulator configured to receive the output light from the first guide surface and to modulate the output light to display an image. 61. A method according to any one of claims 51 to 60, which is a part.   The method further includes controlling the display device to display temporarily multiplexed left and right images, wherein the selective operation of the plurality of light sources is optical at a position corresponding to the left and right eyes of the observer. 62. The method of claim 61, wherein the method is performed synchronously to orient the displayed left and right images within a window.   Detecting the position of an observer across the display device, the plurality of light sources for directing the displayed left and right images in a plurality of optical windows at positions corresponding to the left and right eyes of the observer 64. The method of claim 62, wherein the selective manipulation of is performed according to the detected location of the observer. A directional backlight device,
A waveguide having an input end;
Opposing first and second guide surfaces disposed at different input locations laterally across the input end of the waveguide, the waveguides for guiding light along the waveguide; A reflective end opposite the input end for reflecting input light from the light source and returning through the waveguide, the first guide surface being dependent on the input position Oriented in the plurality of optical windows through the first guide surface as output light after the reflection from the reflection end in the output direction distributed in a direction transverse to the normal to An array of light sources configured to, and
A control system configured to selectively operate the plurality of light sources to supply a drive signal for directing light into the plurality of fluctuating optical windows corresponding to the output direction to the plurality of light sources. The control system senses light incident on the input end from the plurality of light sources after reflection from the reflection end, and determines the drive signal according to the sensed light incident on the input end. A directional backlight device comprising a control system configured to calibrate.   The directional backlight device according to claim 64, wherein the control system further includes a plurality of sensor elements arranged at the input end for performing the sensing of light.   66. The directional backlight device according to claim 65, wherein the plurality of sensor elements are arranged in a region of the input end outside the array of light sources in the lateral direction.   68. The directional backlight device of claim 66, wherein the plurality of sensor elements are arranged on both sides of the light source array, in the input end region outside the lateral light source array.   65. The directional backlight device of claim 64, wherein the control system is configured to perform the sensing of light incident on the input using light sources of the array that are not operated simultaneously.   The plurality of light sources is a plurality of light emitting diodes, and the control system is configured to perform the sensing of light incident on the input using a light source of the array operated in reverse bias. The directional backlight device according to claim 68.   The control system is configured to calibrate drive signals provided to the plurality of light sources, whereby the plurality of light sources output light having a light flux having a predetermined distribution across the array of light sources. 70. The directional backlight device according to any one of claims 64 to 69.   The first guide surface is configured to guide light by total internal reflection and in a direction that allows the second guide surface to exit through the first guide surface as the output light. A plurality of light extraction mechanisms directed to reflect light directed through the waveguide, and the plurality of lights configured to direct light through the waveguide without extracting light 71. A directional backlight device according to any one of claims 64-70, comprising a plurality of intermediate regions between extraction mechanisms.   72. The directional backlight device according to claim 71, wherein the second guide surface has a stepped shape including a plurality of facets as the plurality of light extraction mechanisms and the plurality of intermediate regions.   The first guide surface is configured to direct light by total internal reflection, and the second guide surface is substantially planar for outputting light through the first guide surface; The first of the waveguides is tilted at an angle to reflect light in a direction to change the total internal reflection, and the directional backlight device deflects the light toward a normal to the spatial light modulator. The directional backlight device according to any one of claims 64 to 72, further comprising a deflecting element extending over the guide surface of the directional backlight device.   The directional backlight device according to any one of claims 64 to 73, wherein the reflection end has a positive refractive power in a lateral direction across the waveguide. A display device,
A directional backlight according to any one of claims 64-74,
And a transmissive spatial light modulator configured to receive the output light from the first guide surface and modulate the output light to display an image.   An autostereoscopic display device, wherein the control system controls the display device to display temporarily multiplexed left and right images, and displays the displayed left and right images on the left and right sides of an observer. The display device of claim 75, wherein the display device is configured to selectively operate the plurality of light sources in synchronism with orientation within the plurality of optical windows at a position corresponding to the eye.   The control system further includes a sensor system configured to detect an observer position across the display device, the control system selectively operating the plurality of light sources to detect the observer. 77. The autostereoscopic display according to claim 75 or 76, configured to orient the displayed left and right images into a plurality of optical windows at positions corresponding to the left and right eyes of an observer according to position. apparatus.

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